Assessments of Dietary Intakes of Canadian Armed Forces Consuming Field Rations
by
Mavra Ahmed
A thesis submitted in conformity with the requirements for the degree of Doctorate of Philosophy Department of Nutritional Sciences University of Toronto
© Copyright by Mavra Ahmed 2017
Assessments of Dietary Intakes of Canadian Armed Forces Consuming Field Rations
Mavra Ahmed
Doctor of Philosophy
Department of Nutritional Sciences University of Toronto
2017
Abstract
Military personnel frequently encounter metabolically challenging training or deployment conditions and are known to not eat enough during these field operations. Such conditions also make it challenging to collect accurate dietary intake data using traditional dietary assessment methods.
The specific objectives of this thesis were to assess energy and nutrient intakes of a convenience sample of CAF personnel consuming: 1a) home diets and; 1b) ad libitum field rations at home;
2) ad libitum field rations under different temperature conditions with strenuous activities vs. sedentary in a laboratory setting; and 3) field rations during a 5-day winter weather field exercise. Additionally, 4) a mobile tablet application for dietary assessment of military personnel was evaluated.
Energy intakes were similar between home diets and from ad libitum consumption of field rations at home but CAF participants’ had less than recommended intakes of some micronutrients. In a temperature and humidity-controlled chamber with simulated military-type tasks, energy intakes were similar between treatments of varying temperatures with strenuous physical activity in comparison with the sedentary treatment. Energy consumption did not
ii increase during the rest of the day upon completion of the treatments. During the winter weather field exercise, participants had insufficient energy intakes in relation to their measured energy expenditures, resulting in a significant weight loss. An electronic tablet application was found to be a valid method of assessing dietary intakes from field rations.
Overall, this thesis characterized home diets of a sample of CAF personnel and demonstrated that reduced energy intake is not due to ration palatability, time to prepare or eat the food in an acute setting. Using the best available dietary assessment methodologies, this thesis demonstrated that energy intakes did not increase in harsh environmental temperatures with strenuous physical activities even with ample time to eat and food prepared on request and showed that during a winter weather field exercise, participants exhibited ‘voluntary anorexia’
(under-consumption of food) and weight loss, which has implications for potential impairments in performance and health of CAF personnel during longer duration deployments. Additionally, the use of mobile technology enables accurate dietary intake assessments of military personnel.
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Acknowledgements
Foremost, my deepest gratitude goes to my supervisor Dr. Mary L’Abbé for believing in me and guiding me with her wisdom, insight and encouragement. Thank you, Mary, for your continuous support of my PhD research, your dedication to my success, for helping me grow my critical thinking and nutritional expertise, and for providing me with numerous opportunities that opened so many doors for me. I have admired and been inspired by your balanced approach to hard work and living life to the fullest.
My utmost gratitude goes to Dr. Ira Jacobs, Dr. Len Goodman and Dr. Jonathon Maguire. Dr. Jacobs, thank you for having confidence in my abilities and for challenging my thinking and writing and fostering my intellectual development. I have learned immensely from your mentorship and truly appreciate your dedicated interest in my progress. Dr. Goodman, thank you for providing invaluable feedback every step of the way and for your support and encouragement in helping me achieve my goals. I am grateful for your patient approach in helping me grow academically and professionally. Dr. Jonathon Maguire, I appreciate your commitment to my success and thank you for helping me think critically and beyond my area of focus.
An immense thanks to my examiners, Dr. David Jenkins and Dr. Katherine Gray-Donald, for an engaging defense while challenging me and helping me produce a polished product.
It has been a rewarding experience and a true privilege to be mentored by them over the course of my PhD.
I would like to give special thanks to the Canadian Armed Forces and course coordinators at CFB Meaford for their contribution to this project. I was fortunate to collaborate with staff at Defence Research and Development Canada who enormously contributed to this research with their guidance and support. As well, this project would not have been possible without the enthusiasm of CAF volunteers who kindly gave their time and energy to the experiments.
I am very fortunate to have had Iva Mandic as my collaborator. Iva, I am glad to have met you as a colleague but I thank you for being a friend during our long experimental trial days and I am looking forward to cherishing future years with you as a friend. iv
I would also like to acknowledge L’Abbe Lab ladies for listening to my endless chatter, trying out new places for lunches, concocting endless coffees in Rm87 and for contributing to a lively and vibrant graduate experience. Special thanks to Jodi Bernstein, Mary Scourboutakos, Alyssa Schermel, and Theresa Poon for the much needed friendship and support along the way, providing me with a listening ear on my toughest days, answering my ceaseless questions, for insight on my research and for helping me succeed on this very important journey.
I am also grateful to the staff, professors and graduate students at the Department of Nutritional Sciences for their energy and enthusiasm as well as for providing a productive and an enjoyable learning environment.
Dr. JoAnne Arcand, you have my sincerest gratitude. Thank you for believing in me for the last 8 years and being an absolutely inspirational role model and mentor. Your dedication to my perseverance has motivated me to reach this significant milestone.
Most importantly, I would like to thank my family for their love and encouragement. A special recognition to my dad, Colonel (Ret.) Javed Ahmed, a retired army officer, and to whom I dedicate this thesis. Thank you to my parents, Javed and Atiya, and my siblings, Myra and Ali, for being supportive of every endeavor I have ever chosen to undertake and for cheering me at every moment during the completion of my thesis. I am especially fortunate for my husband Zohaib’s everlasting love and belief in my pursuit of knowledge. I could not have completed this significant chapter of my life without your love, support and encouragement to succeed.
Funding Acknowledgement
I have been fortunate to receive several scholarships and research support for my PhD training. The Canadian Institute of Health Research provided funding through the Public Health Policy Fellowship program and Health Research Forum Travel Award. I have also received the Ontario Graduate Scholarship and additional travel awards from The New York Academy of Sciences and University of Toronto School of Graduate Studies.
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Table of Contents
Acknowledgements...... iv
Table of Contents ...... vi
List of Tables ...... xiv
List of Figures ...... xvi
List of Abbreviations ...... xviii
List of Appendices ...... xix
Chapter 1 Assessments of Dietary Intakes of Canadian Armed Forces on Field Rations ...... 1
Introduction ...... 1
Chapter 2 Background and Literature Review ...... 4
Part 1: Nutrition in Military Personnel ...... 4
2.1 Importance of Habitual Dietary Intakes of Military Personnel ...... 5
2.2 Importance of Energy Balance Under Training or Operational Conditions – The Risk of Suboptimal Consumption ...... 6
2.2.1 Factors Contributing to Voluntary Anorexia ...... 7
2.2.2 Physiological and Psychological Consequences of Suboptimal Dietary Intakes ...... 8
2.2.3 Impact of Temperature Extremes on Energy Intake ...... 10
2.3 Current Feeding Practices and Nutrition Recommendations of Canadian Armed Forces (CAF) Personnel ...... 12
2.3.1 Dietary Reference Intakes: The Nutrient-Based Approach ...... 13
2.3.2 Canada’s Food Guide: The Food-Based Approach ...... 14
2.3.3 In Garrison Feeding ...... 15
2.3.4 Field-Feeding with a Kitchen ...... 15
2.3.5 Field-Feeding Without a Kitchen ...... 16
2.3.6 Combat Ration Program ...... 16
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2.3.7 Incremental Allowances ...... 18
2.4 Current Demographic and Anthropometric Data of the Canadian Armed Forces Personnel...... 18
2.5 Relevant Literature Review ...... 19
2.6 CANADA: Studies on Dietary Intakes of Canadian Military Personnel Under Temperate and Extreme Temperatures (Hot, Cold) ...... 20
2.6.1 Temperate/Hot ...... 21
2.6.2 Cold...... 22
2.7 OTHER NATIONS: Relevant Studies on Dietary Intakes of Military Personnel Under Temperate and Extreme Temperatures (Hot, Cold) ...... 26
2.7.1 Temperate/Hot ...... 26
2.7.2 Cold...... 30
2.8 Section Summary and Rationale ...... 37
2.8.1 Addressing Links to Part 2 ...... 37
Chapter 3 Background and Literature Review ...... 38
Part 2: Dietary Assessment Methodologies ...... 38
3.1 Types of Traditional Dietary Assessment Methodologies...... 38
3.1.1 Measured Food Intake/Food Waste ...... 38
3.1.2 Visual Estimation Method ...... 39
3.1.3 Food Records/ Food Diaries ...... 39
3.1.4 24-hour Dietary Recall ...... 39
3.1.5 Food-Frequency Questionnaires ...... 40
3.2 Technological Innovations in Dietary Assessment Methods...... 41
3.2.1 Mobile Application Technology as a Method of Dietary Assessment ...... 41
3.2.2 Relevant Literature Review ...... 42
3.3 Section Summary and Rationale ...... 44
Chapter 4 ...... 46
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Overall Summary and Research Gaps ...... 46
Chapter 5 ...... 48
Scope, Objectives and Hypotheses of Thesis ...... 48
5.1 Scope and Objectives ...... 48
5.2 Specific Hypotheses...... 49
5.3 Preview of Chapters 6-9 ...... 50
Chapter 6 ...... 53
Dietary Intakes from Canadian Armed Forces Ad Libitum Consumption of Field Rations Compared to Soldier’s Home Dietary Intakes (and Military Dietary Reference Intakes) ...... 53
6.1 Abstract ...... 54
6.2 Introduction...... 55
6.3 Objective ...... 56
6.4 Methods ...... 57
6.4.1 Study Participants ...... 57
6.4.2 Demographic and Anthropometric Assessments: ...... 57
6.4.3 Dietary Intake Assessment ...... 57
6.4.4 Weighed Food Record (wFR) ...... 58
6.4.5 Tablet App ...... 58
6.4.6 Statistical Analyses ...... 59
6.5 Results ...... 60
6.5.1 Participant Demographics and Anthropometrics ...... 60
6.5.2 Dietary Intakes from Ad Libitum Consumption of Field Rations ...... 61
6.5.3 Habitual Dietary Intakes from Home Diets ...... 62
6.5.4 Comparison of Intakes from Habitual Diets with Field Rations ...... 64
6.6 Discussion ...... 67
6.7 Conclusions ...... 72
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6.8 Acknowledgements...... 72
6.9 Funding/Support Disclosure ...... 73
6.10 Conflict of Interest ...... 73
6.11 Addressing Links to Next Chapter ...... 73
Chapter 7 ...... 74
Comparisons of Dietary Intakes of Canadian Armed Forces personnel consuming field rations under acute hot, cold and temperate conditions with simulated strenuous physical activity ...... 74
7.1 Abstract ...... 75
7.2 Introduction...... 76
7.3 Methods ...... 79
7.3.1 Study Participants ...... 79
7.3.2 Experimental Design ...... 79
7.3.3 Demographic and Anthropometric Assessments ...... 80
7.3.4 Dietary Intake Assessment ...... 80
7.3.5 Urinary and Blood Biomarkers ...... 81
7.3.6 Experimental Trials ...... 82
7.3.7 Statistical Analyses ...... 85
7.4 Results ...... 86
7.4.1 Participant Demographics and Anthropometrics ...... 86
7.4.2 Total Energy and Macronutrient Intake during the 8-hour Experimental Trials ... 87
7.4.3 Specific Micronutrient Intakes ...... 88
7.4.4 Caffeine and Water Intakes ...... 89
7.4.5 Total Energy and Macronutrient Intake for post-experimental treatments and for 24-hours ...... 91
7.4.6 Energy Intake in comparison to Energy Expenditure (8-hours and 24-hours) ...... 92
7.4.7 Urinary and Blood Biomarkers ...... 93
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7.5 Discussion ...... 94
7.6 Conclusions ...... 100
7.7 Acknowledgements...... 101
7.8 Author Contributions ...... 101
7.9 Conflicts of Interest ...... 102
7.10 Addressing Links to Next Chapter ...... 102
Chapter 8 ...... 103
Dietary Intakes of Canadian Armed Forces Personnel Consuming Field Rations During a Winter Weather Field Training Exercise ...... 103
8.1 Abstract ...... 104
8.2 Introduction...... 105
8.3 Methods ...... 107
8.3.1 Study Participants ...... 107
8.3.2 Experimental Protocol ...... 107
8.3.3 Demographic and Anthropometric Assessments ...... 108
8.3.4 Energy Expenditure and Body Composition Assessments ...... 108
8.3.5 Dietary Intake Assessments ...... 109
8.3.6 Statistical Analyses ...... 110
8.4 Results ...... 111
8.4.1 Environmental Conditions During Study Phase ...... 111
8.4.2 Study Participants ...... 111
8.4.3 Energy and Nutrient Intakes from Field Rations During Winter Weather Field Exercise...... 112
8.4.4 Measured Energy Deficits ...... 116
8.4.5 Habitual Energy and Nutrient Intakes assessed by the Canadian Food Frequency Questionnaire (CDHQ-II) ...... 116
8.5 Discussion ...... 118
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8.6 Conclusions ...... 123
8.7 Acknowledgements...... 123
8.8 Author Contributions ...... 124
8.9 Conflicts of Interest ...... 124
8.10 Addressing Links to Next Chapter ...... 124
Chapter 9 ...... 125
Validation of a Tablet Application for Assessing Dietary Intakes Compared with the Measured Food Intake/Food Waste Method in Military Personnel Consuming Field Rations ...... 125
9.1 Abstract ...... 126
9.2 Introduction...... 127
9.3 Materials and Methods ...... 129
9.3.1 Study Participants ...... 129
9.3.2 Demographic and Anthropometric Assessments ...... 129
9.3.3 Study Procedures ...... 129
9.3.4 Weighed Food Records (wFR) ...... 131
9.3.5 Tablet App ...... 131
9.3.6 Measured Food Intake/Weighed Food Waste Method (Reference Method) ...... 131
9.3.7 Urinary and Blood Biomarkers ...... 132
9.3.8 Statistical Analyses ...... 132
9.4 Results ...... 133
9.4.1 Participant Demographics and Anthropometrics ...... 133
9.4.2 Smartphone and Tablet Usage ...... 134
9.4.3 Comparison of Tablet App with Measured Food Intake/Food Waste Method ... 134
9.4.4 Comparison of Weighed Food Record (wFR) with Measured Food Intake/Waste Method ...... 136
9.4.5 Relationship between Dietary Assessment Methods and Biomarkers of Intake . 138
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9.5 Discussion ...... 139
9.6 Conclusions ...... 142
9.7 Acknowledgements...... 143
9.8 Author Contributions ...... 143
9.9 Conflicts of interest...... 143
Chapter 10 Overall Discussion ...... 144
10.1 Insufficient Energy Intake in Relation to Energy Requirements ...... 145
10.2 Optimizing Consumption of Macronutrients and Fibre ...... 147
10.3 Less than Recommended Intakes of Micronutrients ...... 149
10.4 Higher than Recommended Intakes of Sodium ...... 151
10.4 Nutrient Intakes Similar Between Males and Females ...... 152
10.5 Acute Operations in Environmental Extremes Impacts Nutritional Biomarkers...... 152
10.6 Novel Methods of Assessing Dietary Intakes of CAF Military Personnel ...... 153
10.7 Overall Limitations ...... 154
Chapter 11 Future Directions ...... 157
11.1 Research ...... 157
11.1.1 Determinants of Nutrient Requirements ...... 157
11.1.2 Nutritional Quality of Field Rations ...... 158
11.2 Policy ...... 160
11.2.1 Emphasis on Importance and Better Understanding of Nutrition ...... 160
11.2.2 Using Technology to Better Understand Nutrition ...... 161
11.2.3 Addressing Under-Consumption of Rations in Field Operations ...... 162
Chapter 12 Key Findings and Implications ...... 163
Chapter 13 Conclusions ...... 165
Bibliography ...... 166
Appendices ...... 182
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Appendix A: Field Ration Menu Items (Experimental Treatments) ...... 182
Appendix B: Field Ration Menu Items (Meaford) ...... 183
Appendix C: Assessment of Habitual Dietary Intake of Canadian Armed Forces Personnel Using the Modified Healthy Eating Index ...... 184
Appendix D: Incremental Allowances ...... 186
Appendix E: Food Satisfaction Surveys ...... 187
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List of Tables
Chapter 2
Table 2.1 Average energy and macronutrient content of a sample of CAF field rations Table 2.2 Current demographics and anthropometrics data of CAF personnel Table 2.3 Summary of studies investigating energy intakes and energy expenditures in CAF military personnel Table 2.4 Summary of studies investigating energy intakes and energy expenditures in military personnel of other nations
Chapter 6
Table 1 Characteristics (demographics and anthropometrics) of the CAF study participants Table 2 Average amount of energy and macronutrients in self-selected field ration packs Table 3 Micronutrient intakes as a proportion of participants below DRI (EAR) and MDRI Table 4 Comparisons between habitual at home dietary intakes and intakes from ad libitum consumption of self-selected field rations at home
Chapter 7
Table 1 Representative military-specific tasks simulated in the environmental chamber Table 2 Characteristics (demographics and anthropometrics) of the CAF study participants Table 3 Energy and macronutrient intakes from self-selected individual meal pack or field rations provided to participants during the 8-hour experimental treatments and for 24-hours (including at home post-treatments) Table 4 Comparisons of energy and nutrient intake in CAF personnel between 8-hour experimental treatments Table 5 Comparison of energy and nutrient intakes in CAF personnel during at home consumption of dinner ration pack after the 8-hour experimental treatments Table 6 Comparisons of urinary and blood biomarkers in CAF personnel between 8-hour experimental treatments
Chapter 8
Table 1 Demographics and anthropometrics of winter weather field exercise training
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study participants Table 2 Average energy and macronutrient composition of field rations selected and consumed by winter weather field training exercise study participants Table 3 Energy and nutrient intakes from field ration consumption during the winter weather field training Table 4 Comparison of daily intakes of selected nutrients from field rations between male and female study participants during the winter weather field training exercise At home dietary intakes of participants prior to the start of the winter weather Table 5 field exercise
Chapter 9
Table 1 Characteristics (demographics and anthropometrics) of the study participants Table 2 Daily energy and nutrient intakes recorded by Canadian Armed Forces (CAF) personnel participants using the tablet app (n = 9) compared to the measured food intake/food waste method (reference method) Table 3 Daily energy and nutrient intakes recorded by CAF personnel using the weighed food record (wFR) 1 and those obtained from the measured food intake/food waste method 2 (reference method)
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List of Figures
Chapter 2
Figure 2.1 Accurate Assessments of Energy Intake & Energy Expenditure Are Needed to Quantify Energy Balance Figure 2.2 The Type of Feeding System is Dependent Upon Operation Type, Condition, Location and Stage of Deployment Figure 2.3 Factors Contributing to Voluntary Anorexia and Impacting Operational Readiness
Chapter 3
Figure 3.1 Summary of Chapters 6, 7, 8 and 9
Chapter 6
Figure 1 Macronutrient intakes of CAF personnel as a percentage (%) of total energy from self-selected field rations Figure 2 Macronutrient intakes of CAF personnel as a percentage (%) of total energy from habitual dietary intakes at home
Chapter 7
Figure 1 Environmentally-controlled chamber laboratory simulation experimental design Figure 2 Macronutrient intake as a percentage of total energy Figure 3 Comparisons of caffeine intake in CAF personnel between 8-hour experimental treatments Figure 4 Comparisons of water intake in CAF personnel between 8-hour experimental treatments Figure 5 Comparison of energy intake with energy expenditure for 8-hours and for post- treatments (as part of a randomized experimental trial)
Chapter 8
Figure 1 Winter Weather Field Training Exercise Experimental Protocol Figure 2 Total energy intake per day from field rations selected by participants compared to consumed energy intake Figure 3 Comparison of macronutrient intake as a percentage (%) of total energy for CAF personnel during the winter weather field training between field rations selected and consumed
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Figure 4 Comparison of sodium consumed from habitual diets at home and self-selected field rations during the winter weather field training to that of the Canadian population
Chapter 9
Figure 1 Repeated Measures Bland-Altman plots of the difference between intakes recorded by the tablet app and those from the measured food intake/food waste method against the mean values for the two methods for (a) energy; (b) carbohydrates; (c) fat; and (d) protein Figure 2 Repeated Measures Bland-Altman plots of the difference between intakes recorded by the wFR and those obtained from the measured food intake/waste method against the mean values for the two methods for (a) energy; (b) carbohydrates; (c) fat; and (d) protein Figure 3 Scatter plots of the relationship between (a,b) urinary urea:creatinine ratio and dietary protein intake and between (c,d) plasma ascorbic acid and dietary vitamin C intake recorded by the (a,c) tablet app and by (b,d) wFR
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List of Abbreviations
CAF Canadian Armed Forces CA Canadian Army CDHQ-II Canadian Diet History Questionnaire II DRI Dietary Reference Intakes EER Estimated Energy Requirement AMDR Acceptable Macronutrient Distribution Range EAR Estimated Average Requirement RDA Recommended Dietary Allowances AI Adequate Intake UL Tolerable Upper Level CFG Canada’s Food Guide IMP Individual Meal Pack LMC Light Meal Combat IA Incremental Allowances MDRI US Military Dietary Reference Intakes FFQ Food Frequency Questionnaire 3DwFR 3-Day weighed Food Record PDA Personal Digital Assistant RCAF Royal Canadian Air Force RCN Royal Canadian Navy TEE Total Energy Expenditure DLW Doubly-Labelled Water DND Department of National Defence DRDC Defence Research and Development Canada
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List of Appendices
Appendix A Field Rations Menu Items During Simulated Experimental Treatments Appendix B Field Rations Menu Items During Winter Weather Field Training Exercise Appendix C CNS Abstract (2017): Assessment of Habitual Dietary Intake of Canadian Armed Forces Personnel Using the Modified Healthy Eating Index Appendix D Examples of Incremental Allowances Appendix E Food Satisfaction Surveys
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Chapter 1 Assessments of Dietary Intakes of Canadian Armed Forces on Field Rations Introduction
Military personnel are at an increased risk for negative energy balance as they are exposed to physical and cognitive stressors during metabolically and environmentally challenging training and operations 1-3. Levels of physical fitness, dietary intake, rest periods and ability to acclimatize to local environmental conditions contribute to determining the operational readiness of military personnel 4,5 . However, nutrition plays a fundamental role in the mental and physical capabilities of soldiers and hence, has a significant impact on operational readiness. Thus, the provision of sufficient nutrition to maintain the performance and health of military personnel is a major factor in the success of operations 2,4,5 .
The Canadian Armed Forces (CAF) population consists of a wide range of CAF members including personnel from the Canadian Army (CA), Royal Canadian Air Force (RCAF), and Royal Canadian Navy (RCN) 6. Wide variability is found in the energy requirements of the members from the Canadian Forces as a result of the differences in activities and trades (e.g. from sedentary non-operational trades to highly active operational trades) 6. As an example, RCN personnel are generally performing tasks limited to the surface area of frigates/fleets, whereas CA personnel are ground-based forces performing tasks and activities over larger distances 6. This thesis focuses on a segment of the CAF population, who may frequently encounter metabolically and environmentally challenging training and operations during deployments for land-based operations.
CAF soldiers are required to be operationally ready for missions that can happen anytime and be spread over great distances 7,8 . As a result, their home dietary intakes and lifestyle habits could potentially contribute to their capability to perform optimally. This applies particularly in situations where nutrient intakes are less than optimal (e.g. field operations), where the nutritional status of an individual prior to deployment could determine the subsequent nutrient status of an individual, thus playing a role in operational readiness 7.
1 2 During deployment or training, CAF personnel endure a wide range of physically demanding activities in combination with physical and cognitive stressors such as, but not limited to, ambient temperature extremes, inadequate consumption of food and water, sleep deprivation and difficult terrain 5,9 . During these situations, food is provided to CAF military personnel through a variety of combat or field rations 10 . These rations are intended to be nutritionally sufficient for standard military operations if all components are consumed 10,11 . However, the rations’ nutritional composition are based on Dietary Reference Intakes (DRIs), which may not adequately consider some of the strenuous activities and arduous conditions that military personnel may experience 10,11 . Additionally, in training and field operations, military personnel often do not consume rations in sufficient amounts to meet the energy requirements of the operational duties 5,12 . This results in a negative energy balance, termed voluntary anorexia, where there is a decrease in food intake, even when the best possible food is available in sufficient quantity, which consequently results in weight loss and potential impairments in physical and cognitive performance 5,12-16 .
Much of the information that we know about the dietary intakes from field rations in CAF personnel, under physically demanding conditions, is dated 9,12,17,18 , with significant gaps in the literature especially in view of recent changes in CAF demographics, advances in technology/equipment, anticipated CAF operating scenarios and differential perceptions of ‘healthy’ foods. Additionally, majority of the earlier research in CAF personnel have not used the best available/gold standard methods for assessing both energy intake and expenditure together to quantify energy deficits in operational settings 9,12,17,18 , hence, the extent to which the energy deficits can be attributed to energy intake or expenditure is not precisely known. Therefore, research is needed to review the current nutritional intake of CAF personnel in relation to energy requirements in order to minimize voluntary anorexia and provide a basis for optimizing performance and health of CAF personnel.
The Defence Research and Development Canada (DRDC) concerns about the potential adverse effects of negative energy balance led to the need to assess dietary intakes of CAF personnel under conditions of strenuous physical activities, temperature stress and extremes of metabolic demands (i.e. from sedentary to strenuous and prolonged physical demands). University of Toronto (U of T) was asked to assist in this matter by conducting a series of experiments on assessments of dietary intake and energy expenditure on convenience samples of CAF personnel
3 at home (habitual intakes), in an experimental trial and during a winter weather field exercise, the latter two under extreme temperatures (i.e. hot and cold) and strenuous physical activity conditions. The focus of this thesis is on the assessment of dietary intakes of CAF personnel. Additionally, this thesis also explores the feasibility of using a tablet, as a novel mobile technological method for assessing dietary intakes of CAF military members. This research was done in collaboration with investigators (Iva Mandic and Dr. Ira Jacobs in the Faculty of Kinesiology and Physical Education, University of Toronto; Eliot Desilets and Dr. Peter Jones at Department of Human Nutritional Sciences, University of Manitoba), who examined assessments of energy expenditure under a Federal Government/DRDC research contract (#W7719-125107/001/TOR) and in collaboration with DRDC Canada (Dr. Len Goodman and colleagues).
Disclaimer: “The opinions expressed in this document are those of the author (Mavra Ahmed) and are not necessarily those of the Department of National Defence, Defence Research and Development Canada or Canadian Armed Forces”
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Chapter 2 Background and Literature Review Part 1: Nutrition in Military Personnel
Military personnel are a unique population as they are engaged in metabolically challenging training and operations 19 . Thus, their operational readiness , defined as optimal physical and mental health, becomes critical for the success of the mission 19,20 . Maintenance of optimal performance and health begins under thermally neutral conditions (e.g. in garrison or at home), before a soldier is deployed for a mission or engaged in training 7,21,22 .
During training and field operations, military personnel are exposed to physical and cognitive stressors that can increase the risk for negative energy balance in this population 1,2 (Figure 2.1). The type of feeding system (e.g. field feeding with/without kitchens, combat/field rations) provided to military personnel are dependent upon, but not limited to, the operation type (e.g. in garrison, in field, training, combat or support), condition (e.g. temperature), location (international or domestic) and stage of deployment (e.g. pre/during/post deployment) 11,12 (Figure 2.2). These logistical and tactical components of a particular deployment pose physical and mental demands on the soldier, thus contributing to a negative energy balance, as expenditures can reach up to 10,000 kcal/day with insufficient intakes to maintain energy requirements 12,15,23 .
It is well established that inadequate energy and nutrient intake can potentially result in injury, prolong recovery time, may depress immune function and can have negative psychological and physiological consequences 5,16,18,20,24,25 . Without a nutritious supply of food and water, the resultant negative energy balance can compromise the mental and physical capability of military personnel, contributing to associated performance impairments and deficits in operational readiness and to an increased risk of compromising in their principal role of combat 12,26 . Thus, ensuring sufficient energy and nutrient intakes are critical to the success of the mission, with direct impacts on the operational readiness of the soldier 26,27 .
5
Figure 2.1: Accurate Assessments of Energy Intake & Energy Expenditure Are Needed to Quantify Energy Balance
Figure 2.2: The Type of Feeding System is Dependent Upon Operation Type, Condition, Location and Stage of Deployment
2.1 Importance of Habitual Dietary Intakes of Military Personnel
Dietary choices and behaviors can impact physical/cognitive performance, sleep and overall health 27 . Thus, dietary habits, including the preference in foods consumed at home, can impact overall health and operational readiness.
Habitual dietary intakes (also referred to as home diets in this thesis) are defined as the intakes of military personnel on a routine/habitual basis, before training and/or deployment, usually under home situations/conditions. To be operationally ready for missions that can happen at any time, span long durations, and be spread over great distances 8, the habitual dietary and lifestyle habits of military personnel must be balanced and healthy. These habitual dietary intakes become increasingly important in situations of low nutrient intake (e.g. field
6 deployments), where the pre-deployment nutritional status of a military personnel could contribute to maintenance of optimal nutrition during-deployment 7.
Assessing the habitual dietary intakes of CAF personnel can help determine their overall nutritional status as well as provide information on preferred food choices. This information is relevant for planning healthcare actions, both in monitoring and in assessing such interventions, as well as for developing food intake guidelines for military personnel in order to optimize both mental and physical performance. To the best of our knowledge, assessments of the habitual dietary intakes of CAF personnel have not been conducted. However, those conducted in the United States (US) military personnel have indicated suboptimal nutrient status with lower than recommended intakes of fruits, vegetables and whole grains 22,28 . Similarly, a study conducted in Thai Active Duty Army Personnel demonstrated suboptimal intake patterns in relation to their recommended intakes 29 . Considering that the success of operations could potentially be compromised in light of suboptimal nutritional status prior to deployment, assessments of habitual dietary intakes/patterns of CAF military members need to be determined.
2.2 Importance of Energy Balance Under Training or Operational Conditions – The Risk of Suboptimal Consumption
Research has indicated that military personnel operating in the field consistently consume insufficient energy, regardless of the amount available 15,18 ; a phenomenon termed voluntary anorexia. Voluntary Anorexia is defined as failure to consume foods that are offered or readily available under situations of extreme stress 5,15 . Of note is the insufficient intake of energy even when conditions demand high-energy expenditures 11 . For example, a study by DeLany et al. 30 , investigated reductions in energy expenditure in response to lower energy intake. The authors found that the energy expenditures of two military groups were the same even though they received different amounts of energy (4020kcal/d vs. 1980kcal/d) 30 . Therefore, when extreme environmental conditions are superimposed on top of the physical and mental demands of operations, military personnel may be at an even higher risk of inadequate energy and nutrient intakes 2 (Figure 2.3). As a result, military personnel may exhibit voluntary anorexia , and are at an increased risk of physiological and psychological consequences from under-consumption.
7 2.2.1 Factors Contributing to Voluntary Anorexia
Voluntary Anorexia in military personnel is a multifactorial issue, which is dependent on several factors 2,19 . These factors include, but are not limited to:
1) Combat/Field Rations; where the palatability, quality, quantity, variety and stereotypes of the rations impact their consumption. 2) Eating Situation; such as meal timing/frequency/duration/regularity, ease of access to food, lengthy or inconvenient food preparation, time available to eat and availability of resources (e.g. potable water) for reconstitution impact consumption. 3) Environment; where harsh environmental temperatures such as extreme cold or heat can add to the physical and emotional stress of field operations, increase the energy and water requirements and impact the time available to prepare and eat and may even affect the quality of the food. 4) Operational Duties; where training schedule, unit commander’s attitudes towards rations and intakes, and load carriage (e.g. clothing/weaponry) can contribute to a compromise between the soldiers’ completion of assigned tasks or consumption of food. 5) Individual Soldier; where circadian rhythms; attitudes towards food and weight loss (e.g. intentional dieting) and the balance between resting/completing tasks of mission and eating impact consumption.
Thus, there is a gap between the amount of energy provided and the amount of energy actually consumed 15 . As repeatedly demonstrated in literature 3,12,15,19,31,32 , these factors play a role in contributing to voluntary anorexia, which can have negative psychological and physiological consequences (e.g. decreased cognitive and physical performance and potentially compromised immunity), thereby, impacting the operational readiness of a solider (Figure 2.3).
8
Figure 2.3: Factors Contributing to Voluntary Anorexia and Impacting Operational Readiness
2.2.2 Physiological and Psychological Consequences of Suboptimal Dietary Intakes
The dichotomy between inadequate intake and high-energy expenditure contributes to the negative energy balance in military personnel. Research has shown that negative energy balance has adverse physiological and psychological consequences 11,33,34 . However, the resultant impairments in physical and mental performance are not only attributed to inadequate energy and nutrient intake but a combined effect of operational duties, commander’s direction and judgment, environmental conditions, individual nutritional requirements and individual motivational levels 33 .
Military personnel typically lose about ~1.5% of their weight in situations where they are provided with, and consume sufficient food and where the tasks last longer than a week 35 . Although short-term under-nutrition resulting in weight losses of <3% body weight over 7 to 30 days has insignificant effects on perceptible health measures 17,36,37 ; such weight loss occurring in an acute time period (e.g. 2 days), usually as a result of dehydration, can have negative impacts on performance 5. A recent study indicated measurable declines in physical
9 performance demonstrated by muscle damage, muscle soreness and fatigue with modest weight losses (2%) during a winter military training exercise lasting 3 and 4-days 34 . The presence of such physical performance declines is probably related to multi-stressors (e.g. inexperience/trade of the soldiers, heavy workload, strenuous physical activity and extreme cold environment) and not just as a consequence of weight loss 34 . Weight losses of 1%-3% have been shown to contribute to 15% impairments in physical performance if they occur in <1 week 18 .
Weight losses of >3% have been documented in cases where rations are consumed for 60 consecutive days without being supplemented with fresh foods 11,36 . These periods of negative energy balance have also been reported to diminish military performance (e.g. reaction time and marksmanship) 13,38,39 . For example, a study conducted on 55 soldiers from a Ranger training program demonstrated weight losses of 16% of their initial body weight over 62 days due to the negative energy balance as a result of the combined effect of reduced energy intake and high energy expenditure 24,33 . When these Ranger soldiers were supplemented with additional food (~400kcal/d) over the subsequent 8-week period while engaged in a Ranger training course, they still lost about 13% of their initial body weight 16,33 . Moderate to severe weight losses (10% - >25%) contribute to impairments in physical performance and neuromuscular coordination 11,16,24,33,40,41 . The Ranger soldiers in the above studies with weight losses of 13%-16% were documented to have reduced grip strength (20%-24%) and peak power declines of 21% in both groups 16,24,33 . Weight losses of greater than 10% can result in serious declines in performance, and potentially suppress immune function 11,16,24 . In the same study as above, the Ranger soldiers demonstrating weight losses of 13%-16% also had suppressed immune function with greater incidences of infections 11,16,24 . However, impaired immunity has been shown to result from multifactorial contributors (and not just weight loss alone) (e.g. stressful operating conditions, high-intensity physical activity, reduced sleep etc.) 16,25,42 . Severe weight losses (25%) have been documented to decrease work capacity by 85%, accompanied by a 30% reduction in hand, arm and back strength 11,40 .
Weight losses of up to 6% over 10 to 45 days do not have measurable impacts on cognitive performance, but the combined effects of inadequate intakes, sleep deprivation and operational tempo result in negative energy balance, which may lead to impairments in cognitive
10 function 5,16 . For example, participants in the Ranger training course were 10%-34% slower completing cognitive tests (decoding, reasoning, memory and pattern recognition tasks) 16 .
In summary, research indicates that physical performance of soldiers might be maintained, provided the soldiers are well-hydrated and the rations available are of adequate nutritional composition, until weight losses approach >10% of initial body weight 5,16,24 . Deficits in cognitive and immune function are often seen when weight losses of >10% occur as a result of the combined effect of suboptimal intakes, extreme fatigue or sleep deprivation and severe environmental conditions 5,16,24 .
2.2.3 Impact of Temperature Extremes on Energy Intake
Research has shown that the energy requirements in climatic extremes are more than for similar activities conducted in temperate environments 3,12,43,44 . This is likely due to the added stress of environmental temperatures as well as additional energy demands from factors related to acclimatization, activity level, hydration level and fitness status of military personnel 3,20 .
There is a paucity of research on vitamin and minerals requirements under environmental stress, although these micronutrients are no less important than macronutrients in contributing to optimal functioning 19,45 . Most of the limited research in this area can be attributed to difficulties in accurately measuring nutrient intakes of military personnel in field conditions. Moreover, vitamins and minerals are generally considered nutrients to keep individuals healthy; however, there might be an increased need for specific micronutrients under situations of temperature stress and strenuous physical activity 1,19,34,46-48 . As such, although, short-term field operations are not likely to lead to micronutrient deficiencies unless there is pre-existing depletion of stores, poor micronutrient status may have profound impacts on prolonged physical and cognitive performances 19 .
Physiological changes and nutrient requirements as a consequence of operating in a hot environment:
Strenuous physical activity results in increases in metabolic rate as well as core body temperature 2,3,49,50 . With the added stress of operating in a hot environment, high sweat rates require adequate hydration levels in order to maintain core body temperature 3,51-54 . As a result, the risk of hypohydration is high for military personnel operating in hot environments, and has
11 been shown to cause significant decreases in performance 3,51,55,56 . Additionally, military personnel lose a significant amount of sodium through sweat losses as a result of operating in a hot environment, and thus require adequate sodium and water intakes 3,54,57 .
Although energy requirements of military personnel are largely dependent on activity levels, loss of appetite has been demonstrated as a consequence of working in a hot environment, which increases the risk of suboptimal energy intake in relation to energy requirements 3,58 . Whether there is a requirement for differential ratios of macronutrients for operating in the hot environment is unknown, however, there is some evidence that carbohydrates might be preferentially used as an energy source for physical activity in the heat 59 .
Very few studies have assessed the impact of extreme hot temperature and effect of exercise on the requirements of vitamins and minerals 3,4 . Some investigators have demonstrated losses of minerals in sweat 60,61 while others have also demonstrated a reduced intestinal absorption of nutrients under conditions of increased body core temperature and inadequate hydration levels 3,62-64 . Additionally, water-soluble vitamins (e.g. B-vitamins and vitamin C) play a role in energy metabolism and there is some evidence for an increased requirement of vitamin C in helping to reduce heat stress 46,65-67 , but whether there are substantial losses in sweat or reduced intestinal absorption of these nutrients (enough to compromise health and performance as a result of operating in a hot environment) still requires further investigation 3,68,69 . The only nutrient for which there may be an increased nutritional requirement in the heat is sodium; however, studies remain equivocal with regards to sodium requirements for military personnel operating in the heat, especially as personnel acclimatize to the hot condition 7,52,70,71 .
Physiological changes and nutrient requirements as a consequence of operating in a cold environment:
In order to maintain core body temperature in the cold environment, the constriction of the vessels in the skin reduces the transfer of body heat to the surface 19 . As a result, individuals are at risk of both freezing (frostbite) and non-freezing (trench foot) cold injuries 72 . However, heat production occurs as a result of shivering or physical activity, which can help guard against cold stress 73 . Shivering increases oxygen uptake, which is accompanied by an increase in cardiac output 74 . This response is also related to an increase in energy requirements in order to sustain physical performance 43 . Additionally, increases in energy requirements of military
12 personnel operating in cold environments are also associated with the increased metabolic rate due to functioning in difficult terrain and wearing thicker protective clothing and heavier work boots 7,19,43,75,76 . As a result, adequate energy and macronutrient intakes are vital for meeting the energy requirements of shivering and physical activity in the cold. Considering dehydration and hypohydration is a concern in cold environments due to exercise-induced respiratory water losses, sweating as well as decreased thirst sensations 19,77,78 , high protein diets may not be appropriate for cold weather work due to increased metabolic water requirements and reduced tolerance for cold 43 .
Very few studies have investigated the changes in requirements of micronutrients as a result of operating in the cold environment 19,43 . Although it is unlikely that military personnel will develop vitamin D deficiency while operating in cold environments, the coupled effect of clothing and insufficient exposure to sunlight at high latitudes might place them at risk of less than optimal concentrations of vitamin D, especially in relation to intense physical activity 47 . Although high sodium intake can lead to diuresis, which is a concern for extreme cold environments, sodium losses through sweating due to heavy clothing and demanding physical work may also occur under cold conditions, similar to as has been shown in hot environmental conditions 19,48 . Some investigators have demonstrated increased acclimatization to cold with increasing levels of blood ascorbic acid levels (vitamin C) 79 , but whether vitamins and minerals play a role in maintaining core body temperatures, decreasing the risk of hypothermia or contribute to minimizing the risks for stress fractures still require further investigation.
Overall, it is clear that maintaining adequate nutritional and hydration status is integral to maintenance of individual operational readiness. Therefore, knowledge of the nutritional requirements of CAF military personnel across training and field operations is important if combat rations are to feed the military personnel during operations 7. However, in order to satisfy nutritional requirements and devise strategies to enhance performance, we need to determine nutritional intakes and requirements under such situations 7.
2.3 Current Feeding Practices and Nutrition Recommendations of Canadian Armed Forces (CAF) Personnel
The current feeding practices for CAF personnel during deployments/training adhere to CAF Food Services standards, which follow the Dietary Reference Intakes (DRIs) recommendations
13 and Canada’s Food Guide (CFG) 10,11 . DRIs are considered a nutrient-based approach that estimates the amount of nutrients required to maintain good health 80 , whereas CFG is a food- based approach that refers to the types and amounts of a variety of foods to maintain good health 81 (Further Discussed in Sections 2.3.1 and 2.3.2). The nutrition recommendations (specifically the type of feeding provided e.g. fresh foods or field rations) for CAF personnel in garrison, in the field and/or in combat/training depend on the logistical and tactical components of the deployment situation 5,11 .
2.3.1 Dietary Reference Intakes: The Nutrient-Based Approach
Dietary Reference Intakes (DRIs) are a set of energy and nutrient-based reference values that are used for planning and assessing diets of healthy individuals 80 . The reference values are comprised of Estimated Energy Requirement (EER), Acceptable Macronutrient Distribution Range (AMDR), Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI) and Tolerable Upper Intake Level (UL) (Box 1) 80 .
Although, DRIs are national nutrient requirements designed for the healthy Canadian adult population, they are also used to guide the nutrient content of the CAF field rations 10,11 (See Section 2.3.6).
Box 1: DRI Definitions 80,82
Estimated Energy Requirement (EER): The EER is an estimate of energy requirements of an individual of a defined age, gender, weight, height and level of physical activity.
Acceptable Macronutrient Distribution Range (AMDR): An AMDR is a range of intakes of an energy source (carbohydrates, fat and protein) that is associated with a reduced risk of chronic disease while providing adequate amounts of macronutrients. The AMDR has an upper and lower boundary, which indicates the risk of chronic disease or the risk of insufficient intakes that affect long-term health if an individual’s intake is below or above this range. An AMDR is not set for total fibre because it is an insignificant contributor to total energy intake and there is no known evidence of adverse effects associated with its consumption.
Estimated Average Requirement (EAR): The EAR is a nutrient intake that meets the requirement of 50% of healthy individuals in a particular life stage/gender group. It is used to
14 estimate the proportion of a group in meeting their requirements. Although it can be used to examine the probability that usual intake is inadequate for individuals, it is not meant to be used as a goal for daily intake by individuals because the EAR represents the estimated median requirement which exceeds the requirements of half of the group and falls short of the other half.
Recommended Dietary Allowance (RDA): The RDA is an estimate of an average nutrient intake that meets the requirements of 97-98% of healthy individuals in a particular life stage/gender group. It is used as a goal for an individual’s usual intake as it falls above the requirements of most people, it is considered almost adequate.
Adequate Intake (AI): The AI is a recommended average nutrient intake level that is based on observed or experimentally determined approximations of nutrient intake by a group of healthy individuals when there is insufficient evidence to establish an EAR and thus an RDA. The AI is expected to meet or exceed the needs of most individuals in a particular life stage/ gender group.
Tolerable Upper Intake Level (UL): The UL is the highest average nutrient intake level that likely poses no risk of adverse health effects for almost all individuals in a particular life stage/gender group. Although the UL is not a recommended intake level, it is used to assess the potential risk of increasing adverse effects when an individual’s intake exceeds the UL. Although, an UL is not available for all nutrients because of insufficient evidence, this does not mean that consuming excess amounts may not lead to adverse effects.
2.3.2 Canada’s Food Guide: The Food-Based Approach
Canada’s Food Guide (CFG) is an educational tool designed to help individuals make healthy food and beverage choices 81 . CFG recommends consuming a variety of food types from four major food groups (Vegetables and Fruits, Grain Products, Milk and Alternatives, and Meat and Alternatives). It also recommends the number of food guide servings per day for individuals in a particular age/gender group 81 . The CAF field rations contain a variety of food and beverage items that aims to include the four major food groups and contain low levels of saturated and trans fat 10 .
15 2.3.3 In Garrison Feeding
In garrison feeding refers to consumption of foods that are freshly prepared by the kitchen staff in a garrison dining facility. The garrison dining facility is a cafeteria-style service that contains healthy fresh food options and is typically used by personnel during training or when residing at base stations 10 .
Although, garrison feeding results in consumption of approximately 3200 kcal/day, regardless of daily activities (which is sufficient to support energy requirements of support personnel – energy expenditures average 3000 kcal/day) 21 , this level of energy intake is inadequate for personnel engaged in more strenuous activities such as combat training, where energy expenditure can average ≥4000 kcal/day 11,21 . Although studies assessing adequacy of garrison feeding have not demonstrated weight changes, most of these are short in duration and indicate that the nutrient goals (e.g. adequate energy intake, consumption of nutritious food) of highly active military personnel may not be fully met by eating in the dining facility alone 21,83 .
It is recognized that only a small percentage of CAF members consume the majority of their meals at CAF dining facilities and may supplement this intake with outside foods 21 , although garrison feeding is designed to facilitate effective training by ensuring that military personnel are consuming adequate nutrition 10,11 .
2.3.4 Field-Feeding with a Kitchen
During deployment, operation type, environmental conditions, location and stage of deployment can impact the feeding system 84 . These feeding systems can include mobile kitchen trailers, re-locatable tented camps, permanent/semi-permanent kitchen facilities, fresh rations or provision of pre-packaged ration packs (also known as combat/field rations or Individual Meal Packs (IMPs) ) 11,84 .
Mobile kitchen trailers are highly portable, making them an efficient and practical choice for domestic or international missions lasting up to 6 months 84 . Re-locatable tented camps are typically used for operational missions of longer durations (up to 2 years) 84 . For operations lasting beyond two years, permanent or semi-permanent kitchens are utilized 84 . Fresh rations (Section 2.3.5) or pre-packaged ration packs (Section 2.3.6) can be provided in addition to one of the above kitchen facilities (e.g. permanent or semi-permanent kitchens) 11 .
16 2.3.5 Field-Feeding Without a Kitchen
In situations where it is not always possible for an army unit to be close to a kitchen or a dining facility, CAF certified food service units provide crew served meals that allow for the provision of fresh foods to the unit 11,84 . However, these fresh rations are difficult to store and deliver and can only feed a limited group of people. In addition, fresh rations have a food safety risk associated with its delivery, as non-food services trained personnel often handle these rations, and items are also of a perishable nature 11,84 .
2.3.6 Combat Ration Program
Under circumstances where it is not always possible to set up a kitchen on site of missions and/or training and where it is either impractical or infeasible to provide fresh foods, military personnel are supplied with pre-packaged rations packs (henceforth known as combat/field rations or IMPs) 9,11,84 .
Canadian field rations are shelf-stable, pre-cooked, ready-to-eat foods and beverages designed and developed to meet the dietary and nutrient requirements of the CAF military personnel 11,84 . Field rations offer common foods based upon Canadian preferences and eating patterns and contain several meatless options 10 . Although these rations are intended to be nutritionally sufficient for standard military operations, the DRIs used in the development of these field rations may not adequately consider some of the strenuous and demanding operations that military personnel encounter either during training and/or combat operations 11 .
These rations are not meant to be used exclusively beyond 30 consecutive days and military personnel are supplemented with fresh foods after 14 days of exclusive subsistence on field rations where possible 9,10 . Fresh foods are not always relied upon for nutritional adequacy in situations where supplementing with fresh foods is not always possible after 14 days 11 . Missions may be longer than intended, thus some CAF personnel may end up consuming combat rations for the duration of their deployment 11 .
The combat ration program consists of five types of rations that are intended to vary in nutritional requirements due to diverse activities and operational duties of military personnel. These fives types of rations are 10 :
17 Individual Meal Pack (IMP) is a ration pack that is typically supplied during deployment and/or training (Table 2.1). Each IMP weighs about 0.73 kg 10,85 and contains a main entrée, a dessert, sport drinks, bread, jam/peanut butter/honey, 2 hot beverages (e.g. Nescafe 3-in-1 sachets or instant coffee powder), candy/mint and condiments (e.g. hot sauce, ketchup) (Appendices A & B). The IMP requires minimum preparation or reconstitution of the dehydrated products. The retort pouch packaging of the main entrée and/or dessert allows for contents to be consumed cold or heated (with body heat, heating sleeves or boiling water) 10,86 .
Light Meal Combat (LMC) pack is typically provided under physically demanding circumstances, where three daily IMPs may become insufficient to meet the nutritional needs of the military personnel 10,85 . The typical LMC weighs 0.42 kg and contains a source of protein, granola bars, dried fruit/candy and sport drinks (vitamin-C fortified drink crystals) 85 (Table 2.1). Although LMCs provide a source of quick nutritionally dense foods, LMCs are not recommended for consumption in quantities of more than three and/or for more than 48 hours 10,85 .
Table 2.1: Average energy and macronutrient content of a sample of CAF field rations Individual Energy (kcal) Carbohydrates (g) Total Fat (g) Protein (g) Meal Pack Breakfast 1344 221 41 31 Lunch 1432 224 41 43 Dinner 1317 200 39 42 Total (% of 4093 645 (63%) 121 (26%) 116 (11%) total energy) LMC* 1125 203 (72%) 25 (20%) 35 (12%) DRI/AMDR** 2800-3200 338-488 (45-65%) 67-117 (20-35%) 75-262 (10-35%) (/day) The averages are based on 6 field rations or individual meal packs / meal type (6 Breakfast, 6 Lunch and 6 Dinner). *Light Meal Combat (sport drinks provided within the Individual Meal Pack and LMC are vitamin-C fortified drink crystals); **Dietary Reference Intakes/Acceptable Macronutrient Distribution Range (AMDR) (an example energy range for a moderately active to highly active 70kg male); Carbohydrates, fat and protein AMDR based on average 3000 kcal/day.
Basic Survival Food Packets are designed for use under circumstances of minimal energy expenditure and where access to water may be limited 11 . The ration contains starched jelly candies, supplementary drinks and emergency drinking water, providing 500 kcal composed entirely of carbohydrates 11 .
18 Alternative Meal Packs contain vegetarian options that are either Halal or Kosher certified and contain approximately 1200 kcal (50% of energy from carbohydrates, 38% of energy from fat and 12% of energy from protein) 10 .
Arctic or Tropical Food Supplements are supplied during extreme heat or cold environmental conditions where the need for additional energy/nutrients/fluids is warranted 10 . These rations are similar to Basic Survival Packets, providing at least two days of nourishment 9.
High Protein Supplement Ration Packs often provide a good source of protein when IMPs are consumed for longer periods of time and fresh food supplementation is not available 11 .
2.3.7 Incremental Allowances
Basic Food Cost (BFC) is a standard food allowance, expressed as a monetary value, which refers to the cost of one meal day (e.g. 3 IMPs) provided in garrison or in the field 84 . A meal day refers to the amount of food required for the provision of three meals over a 24-hour period 11,84 . When the standard allowances are insufficient to meet the requirements of military personnel (e.g. under situations where greater sustenance may be warranted), Incremental Allowances (IA) may be authorized 84 . IA refers to the cost of in addition and above the BFC that is required to feed the soldiers (Appendix D) 11 . The IA is at the discretion of the unit commander’s authorization and based on additional financial resources rather than on empirical measurements of nutritional or physiological requirements 11 .
2.4 Current Demographic and Anthropometric Data of the Canadian Armed Forces Personnel
Currently, the Canadian Armed Forces stands at a strength of approximately 119,000 members, which includes 68,000 regular, 27,000 reservists, 5000 rangers and 19,000 supplementary reserves 87 . Table 2.2 shows the demographic and anthropometric data collected from a representative sample in 2012 from a total of 2205 male and female CAF personnel (1890 males and 315 females), including personnel from the CA, RCAF and RCN 6.
19 Table 2.2: Current demographic and anthropometric data of CAF personnel (n=2205) 6†.
Characteristics CAF Personnel (n = 2205) Age (years) * 34 ± 9 Sex ** Males 1890 (86%) Females 315 (14%) Weight (kg) * 79 ± 14 Height (m) * 1.7 ± 0.1 Body Mass Index (kg/m 2)* 27 ± 5 Ethnicity ** Caucasian 2043 (92.7%) Asian 23 (1%) African American 21 (1%) Hispanic 15 (0.7%) Other 103 (5%) *Mean ± standard deviation (SD); ** n (%); †Data collected in 2012 using the Canadian Forces Anthropometric Survey at 14 bases and wings across Canada with a representative set of anthropometric data of CAF personnel across four strata: age, sex, Military Occupation Survey Identification and service 6. Body size and shape data of 2205 CAF personnel were obtained using measuring tapes, calipers, 3D laser scans of the whole body, head, hands and feet and 2D photogrammetry 6.
In terms of weight, the CAF military population is similar to the Canadian population with recent increases in overweight and obesity, as indicated by the mean Body Mass Index (BMI) 6. However, the BMI range varies among the CAF personnel depending on the trade, rank and service 6. For example, military personnel employed in mostly sedentary activities generally have a higher BMI in comparison with personnel employed in arduous operations. As a result of the trade, overfeeding in the field in relation to low energy expenditure is also found in some members of CAF population 6. However, the purposes of this thesis was to assess the phenomenon of under-feeding in the field in relation to very high energy expenditures when a segment of the CAF population is deployed for physically and psychologically demanding field operations or missions.
2.5 Relevant Literature Review
The following studies (in Sections 2.6 and 2.7) were identified that have investigated measured energy intakes and/or energy expenditure in CAF and in military personnel from other nations and are summarized in Tables 2.3 and 2.4, respectively. Inclusion of studies (up to year 2016)
20 were limited to those that focused on energy intake and expenditure in temperate, hot and cold environmental conditions over a wide range of physical activities; assessed macronutrient and micronutrient intakes under the above-mentioned conditions; and were conducted in either CAF military personnel (for studies in Section 2.6) or in armed forces military personnel from other nations (for studies in Section 2.7) when training or operating in the field. The following criteria were used to exclude studies: studies of energy demands in high-altitude environmental conditions, nutritional needs in relation to psychological and emotional stress, nutritional intakes and requirements in dining facilities and/or in garrison feeding, energy intake/expenditure in relation to appetite. Eligible studies (based on inclusion/exclusion criteria) were identified from the research contract report published by Mandic et al.,11 . Additionally, an independent electronic search was carried out in PubMed, military databases (e.g. Defence Technical Information Center (DTIC) and Defence Research and Development Canada (DRDC)) and through Google searches to locate additional articles meeting the inclusion/exclusion criteria.
Many of the following studies have used different types of dietary assessment methodologies to assess diets. Although the following literature review will highlight some of the relevant advantages and limitations of using these dietary assessment methodologies, Chapter 3, Part 2: Dietary Assessment Methodologies of this thesis provides additional discussion on the use of these techniques to assess diets. This section focuses on the discussion of literature relevant to assessments of both energy intake and expenditure in military personnel in order to quantify/attribute energy deficit as a consequence of operating or training in the field.
2.6 CANADA: Studies on Dietary Intakes of Canadian Military Personnel Under Temperate and Extreme Temperatures (Hot, Cold)
Environmental stress can place additional physiological demands on the soldier’s ability to perform a task (as discussed in Section 2.2.3) 2,15,18 . As a result, energy requirements are higher in temperature extremes than for similar activities conducted in temperate environments 12,43 . Such conditions could potentially compromise both physical and mental health of military personnel, thereby impacting operational readiness and performance 2,19 .
21 The following studies were identified that have investigated measured energy intakes and/or energy expenditure in CAF military personnel and are summarized in Table 2.3.
2.6.1 Temperate/Hot
Studies assessing energy expenditure of military personnel in hot environments (>25 °C; depending upon humidity) have reported energy requirements to range from 3300 kcal/day to 5500 kcal/day 7,11,24,35 , which were similar to the energy expenditures reported for a temperate climate but slightly less than for the cold environment. However, heat stress can significantly impact energy requirements, where the levels of hydration, humidity, fitness, clothing and heat acclimatization can play a role in maintaining core body temperature and preventing dehydration and hyperthermia 11,15,54 . Additionally, some researchers have postulated loss of appetite in a hot environment, where the difference between intake and requirement may further increase energy requirements 3,88 . To the best of our knowledge, studies conducted to assess dietary intakes of CAF personnel in relation to energy expenditure during hot environmental conditions were not found.
Studies assessing energy expenditure in a temperate environment (10 °C to 25 °C) have reported requirements to range from 3300 kcal/day to 6000 kcal/day 11,18,36,89 . One of the earliest studies contributing to assessments of dietary intakes of CAF personnel on rations was conducted in 1989 18. This study was designed to investigate additional carbohydrate supplementation on maintenance of skeletal muscle glycogen during a field trial and associated impairments in physical performance post-trial in CAF Commandos 18 . Using the measured food intake/food waste method, this study found that CAF soldiers (not on supplementation) consumed about 71% of the energy (2571 kcal/day) from the provided rations, with total energy of 57% from carbohydrates, 26% from fat and 14% from protein, on a 5-day field exercise under temperate conditions. This study used what is considered the gold standard for assessing dietary intakes (measured food intake/food waste method), however, platoons were given allotted time periods (30-60 minutes) for each meal and estimations of energy expenditure were indirect, thus the information contained within the trial may not appropriately express the energy deficits as a consequence of continuous intense physical activities. Although the study is dated and provided limited information for intakes of additional nutrients (including micronutrients) of CAF military personnel 18 , it was one of the first to show potential energy deficits as a result of
22 a voluntary reduction in energy intake and high energy expenditure levels in CAF personnel in a temperate environment.
The above findings are similar to a study conducted by Hatton et al. 9 in which the authors investigated the dietary intakes of CAF soldiers consuming combat rations and personal foods in a temperate environment. The investigators used a food intake/waste collection method with a 48-hours food intake questionnaire (a food frequency questionnaire designed with combat ration menu items) to assess dietary intakes. Energy intake was 3516 kcal/day in the group consuming combat rations with personal foods, whereas the participants on rations only had an energy intake of 2714 kcal/day. Participants had low intakes of potassium, calcium, vitamin C and folate. Although the consumption of personal foods resulted in an increase in energy intake (~800 kcal/day) by soldiers, military personnel were still not eating enough in relation to the amount of energy they were expending (which was not measured, but rather estimated using previous literature) 9,11 . Although the assessments of dietary intake data were well-conducted (as investigators validated the use of the self-reported questionnaires), this study assessed only two days of dietary intake data and it is likely that participants may still have misreported items using questionnaires under conditions of stress (e.g. extreme environmental temperatures and/or physically demanding activities). Thus, the precise estimate of the magnitude of energy deficit as a consequence of operating or training in temperate/hot environments is unknown for CAF military personnel, considering the limitations identified in the above studies.
2.6.2 Cold
Based on studies assessing energy intake/expenditure in cold environments (including arctic conditions, temperature <10°C), energy requirements in the cold environment are reported to range from ~ 4000 kcal/day to >6000 kcal/day 11,17,90,91 but can significantly increase due to physiological thermoregulatory responses (e.g. shivering), although most energy expenditure in cold environments is attributed to heavier clothing and difficult terrain 11,15,19,43 .
Studies in CAF soldiers conducting exercises/training in cold environments have found that participants consumed a range of energy intakes (61% to 80% of expenditure) 17,18 . Jones et al. 17 measured energy expenditure (measured using the gold standard of doubly-labelled water (DLW)) and energy intake (from combined ration packs and local food consumption; assessed using self-reported food records) of CAF military personnel conducting light to moderate
23 intensity physical activities in a cold environment. The authors reported 61% of total energy consumed in relation to energy provided in the ration packs (total provided was 4350 kcal) and in relation to the energy expended (4317 kcal) 17 . Considering that the energy needs were being met from both rations and local foods, it is difficult to estimate how much of the energy provided was consumed from rations only and whether participants may have underreported their intake (one of the limitations of using self-reported food records/diaries; for further discussion, see Chapter 3). The data on weight loss suggested that the energy intakes were closer to the energy expended, indicating potential under-reporting by soldiers in this study 17 . Thus, it is difficult to know the precise estimates on the magnitude of weight loss due to an energy deficit 92 .
Hatton et al., 9 conducted the most recent study (although this was also a decade ago) in CAF soldiers that investigated dietary intakes from combat rations and personal foods in comparison with DRIs in an operational cold setting 9. Participants were asked to record food and beverages consumed using two 24-hour food frequency questionnaires with a list of combat ration menu items and pre-specified percentages of consumption (100%, 75%, 50%, 25%) given. The investigators found that participants consuming both combat rations and personal foods (n=48) had an energy intake of 3415 kcal/day with 47% of total energy from carbohydrates, 38% from fat and 14% from protein. Intakes of potassium, calcium, vitamin C, and folate were low, whereas sodium intake exceeded the UL (2300mg). Similar results with respect to micronutrients were found for participants consuming rations only (n=24) although their energy intake was 2475 kcal/day. The authors concluded that soldiers were not consuming enough food in relation to the energy they were expending 9. However, the authors did not measure energy expenditure (which was approximated to 4400 kcal/day based on previous literature) and weight loss/gain was also not measured. Although the investigators used a validated FFQ, it is likely that participants may still have misreported food items, particularly from personal foods (for further information on the use of dietary assessment methods, see Chapter 3). Additionally, the authors identified difficulties with completion of the questionnaire on the second day due to the intense pace and tempo of the military tasks, which may have also resulted in imprecise measures of intakes during the cold operation 9.
Most of the studies conducted in CAF personnel examining dietary intakes are dated, did not fully profile the energy and nutrient intakes of CAF personnel (e.g. missing data on
24 micronutrients), and did not measure or used indirect measures of energy expenditure (e.g. heart rate monitors). Additionally, only one study out of 3 (the study by Hatton et al., 9 was counted as one study) used a direct method of assessing energy expenditure (doubly-labelled water), however, the use of self-reported food records limits the accurate assessments of dietary intake in this study 17 . Although, the extent to which energy deficits can be attributed to precise estimates of energy intakes versus expenditure is not fully known, these studies contributed vital information on potential energy deficits as a consequence of a voluntary reduction in energy consumed in relation to energy expended in CAF personnel, under various temperature and activity conditions. Furthermore, although the stress from both physical and psychological events surrounding military operations may vary between sexes, there is paucity of data in CAF personnel on differences between male and female nutrition 2. Additionally, data are limited on the assessment of biomarkers in relation to ration consumption and under periods of extreme environmental temperature in CAF personnel. Considering that nutritional biomarkers act as indices of biological or physiological responses to dietary behavior (i.e. consuming field rations) 93,94 , a better understanding of changes, if any, in biomarkers can help assess the impact of consuming field rations on nutrient status. Therefore, all these gaps point to the need to conduct current assessments of dietary intakes of CAF personnel under varying temperatures and demanding physical activity levels.
Table 2.3: Summary of studies investigating energy intakes and energy expenditures in CAF military personnel Sample (n) Location; Days Dietary Energy Type of Energy provided Energy consumed Energy Micronutrients Weight (sex) reference temperature assessment expenditure Activities (EP) (kcal) in (EC) (kcal) (% EP) Intake/Energy assessed loss method (EE) rations & (C/F/P)† Expended ¥ (kg) method (kcal/d) CF * CFB ** 5 Measured Heart rate Endurance IMP ‡ (~3600) 2571 (71%) Estimated as N/M 1.1 ±0.3 Commandos Petawawa; food intake/ monitors; activities 57/26/13 43% n=30 Temperate food waste portable (males) 18 (N/R) method metabolic IMP + 240g 3217 (71%) Estimated as 1.9 ±0.2 device Carbohydrates 67/20/10 54% (>6000) (~4500) CF soldiers/ CFB 2 Food intake Estimated Various IMP IMP 3516 2714 N/M Potassium, N/M joint Wainwright; questionnaire from intensities (4037) + (4037) (87%) (67%) Estimated as calcium, iron, sovereignty Temperate (48h) + food literature personal 49/34/15 49/34/14 80% and 62%, Vitamin A, C, n=72 (10 °C to waste review foods respectively folate, sodium (males) 9 20 °C) (~4400) CF soldiers/ CFB 4 Food intake Rations Φ Rations 3415 2475 N/M joint Pangnirtung; questionnaire (5307) + (5307) (64%) (50%) Estimated as sovereignty Cold (48h) personal 47/38/16 (51/14/35 78% and 56%, n=50 (-8°C to food respectively (males) 9 7°C) Canadian CFB Iqaluit; 10 Self-reported DLW § Light to IMP (4350) + 2633 (61%) 61% N/M 0.6 ±1.0 soldiers Cold food records (4317) moderate local foods 48/34/18 n=20 (<-30 °C) intensities (males) 17 *Canadian Forces; ** Canadian Forces Base; †Carbohydrates/Fat/Protein as % of total energy consumed; ‡Individual Meal Pack; Φ Rations refers to a combination of IMP and Light Meal Combat (LMC) Packs; §Doubly-labelled water; EE = Energy Expenditure; EP= Energy Provided in rations; EC = Energy Consumed; %EP = Energy consumed as % of energy provided (from amount in EP from rations/IMPs only and not personal/local foods unless otherwise indicated); ¥Energy Intake/Energy Expended (EI/EE) = Energy intake as % energy expended where estimated (calculated based on indirect or reported measures of EE by authors in the study) and/or measured and reported by investigators in their studies; N/R = Not reported; N/M= Not measured.
25
2.7 OTHER NATIONS: Relevant Studies on Dietary Intakes of Military Personnel Under Temperate and Extreme Temperatures (Hot, Cold)
Studies discussed in this section pertain to assessments of dietary intakes in samples of military personnel consuming rations under temperate, cold and hot conditions. These studies have been conducted in military personnel from nations other than Canada, and thus may not be generalizable to the Canadian military population due to Canada’s unique ethnic mix, differences in nutrient composition of the ration packs, differences in climate or terrain, training requirements, military doctrine and demands on physical activity levels. However, consideration of the international military scientific literature may provide some of the additional information needed to guide the interpretation of results in this thesis. The following studies have been summarized in Table 2.4.
2.7.1 Temperate/Hot
Studies have shown energy consumption to range from 48% to 99% of energy expended in hot and temperate climates in military populations from other countries 11,13,14,36 . Table 2.4 details each of the following studies with respect to information on specific methods of data collected on energy intake, energy expenditure, temperature, activity type and rations provided.
Under a simulated urban combat training course in a temperate/hot environment (temperature range 8.1 to 33.6 °C), US soldiers (n=36) engaged in high intensity combat operations consumed 48% of the energy expended (measured using doubly-labelled water) in comparison with soldiers engaged in low intensity activity, who did not differ in the energy expended and consumed 13 . This suggests the soldiers engaged in high intensity activities were not meeting their energy requirements. However, the method used to determine food intake differed between the two groups. Soldiers engaged in low intensity activity were stationed at a location with a dining facility which allowed the investigators to use the visual estimation technique to assess intakes, whereas intakes for soldiers engaged in high intensity operations and in various training locations was collected by the method of measured food intake/food waste 13 . The accuracy of the visual estimation method is dependent on the trained personnel, and thus
26 27 researcher bias can alter the estimates of the food consumed 95 (for further discussion on visual estimation technique, see Chapter 3). Therefore, it is possible that investigators may not have found a significant difference in energy consumed in comparison to expended for the group with the low intensity activity because of limitations associated with visual estimation method where the trained researcher may have over- and/or under-estimated food consumed for participants. Although the method of measured food intake/food waste is considered the gold standard in assessing intakes 96 , there is potential that the participants did not return complete wrappers and trash from the rations and that food may have been shared among participants, making it harder to assess intakes for individuals in relation to energy expended. As such, the dietary assessment method used could have significantly impacted the relationship between the amounts of energy consumed in relation to energy expended. Nevertheless, the authors found a significant reduction in body mass (3.3 ± 1.9 kg) (measured using standard weight scales and skinfold thickness measurements) for soldiers in the high intensity operations, confirming a large energy deficit 13 . However, these authors did not report micronutrient intakes, and the food consumed over the course of the study was a combination of ration packs and dining facilities and thus, it is difficult to apply those results on energy deficits in relation to intake and expenditure for military personnel subsisting on rations alone when operating/training in the field.
In contrast, under temperate conditions (-1.1 °C to 16 °C), DeLany et al., 30 and Askew et al., 14 found special operations soldiers to consume 77% of the total energy provided in the form of complete Meal, Ready-to-Eat (MRE) rations (82% of energy expended) compared to soldiers given restricted rations (2000 kcal/day), who consumed 97% of total energy provided (59% of the energy expended) 14,30 . The gold standard method of DLW was used to measure energy expenditure, however to assess ration consumption in the field, the soldiers used self-reported food records, designed similarly to food frequency questionnaires with a list of ration items and pre-specified food portions (¼, ½, ¾ or all) 14 . Authors indicated validation of the use of this log book/food record in previous field studies (reference not provided in original study). The relative higher intake of energy (77%) in this study in comparison to the energy intake found in the study by Margolis et al. 13 , where participants consumed 64% of the energy provided, can be attributed to the differences in the methods used in assessing intakes as well as the differences in the sample by trade (discussed below). Although the use of a log book with pre- specified portion sizes might result in inaccurate estimates of intake, the use of standardized
28 military rations with specified amounts reduced this systematic bias. Additional weekly checks of the log books by dietitians in this study may have also reduced respondent bias. Special operations forces soldiers (not in training) are more likely to consume sufficient energy in relation to their energy expenditures compared to soldiers in training, as they are familiar with the importance of eating (e.g. carry propane fuelled grill to heat the food, attitude towards eating, meal timing etc.) 5,97 . This is also evident by the lower energy deficits found in this study (except for the group who were provided with MRE-restricted rations). In this same study, investigators reported micronutrient intake to be adequate in comparison with US Military Recommended Dietary Allowances (MRDA) values except for calcium and magnesium (for the MRE group) and vitamin A (for the MRE-restricted group) (group mean intakes compared to the lower range of MRDAs) 14 .
Similar to DeLany et al. 30 and Askew et al. 14 , Consolazio et al. 37 found special operations forces soldiers consumed a higher amount of energy (94% of energy provided) with total energy from carbohydrates, fat and protein to be within the MRDA recommendations in a hot climate (30 °C to 34 °C). In addition, these investigators found adequate intakes of thiamine, riboflavin, niacin, calcium and magnesium but inadequate intake of potassium, while sodium intake exceeded the recommendations 37 . In these studies, the soldiers were either heat acclimatized and part of the special operations force, thus, similar to the sample in the above study 14,30 , the experience and training of a military personnel is likely to play a role in ensuring that soldiers were self-consuming sufficient amounts of energy and nutrients. However, the authors did not specify the dietary assessment method used but indicated that some participants consumed their rations completely and some did not 37 . Although, the authors reported weight loss of 5.5 kg/man (estimated from 292 g/man/day), measurements of energy expenditure were not reported; therefore, the precise estimates on energy deficits are unknown. Despite the uncertainty regarding the accuracy of the dietary intakes reported, this study provides vital data on micronutrient intakes and biochemical measures of minerals in military personnel (for further discussion, see Consolazio et al., 37 and Mineral Requirements for Military Personnel, Committee on Military Nutrition Research, Food and Nutrition Board, Institute of Medicine, 2006 70 ).
British military personnel undertaking frontline operational duties were assessed for body composition, energy and food intake and energy expenditure while consuming rations in a hot
29 climate 4. The authors of this study found that although the energy intake (2531 kcal/day; 70% of the energy expended) in this sample was lower than the energy expended (3626 kcal/day), the soldiers were able to maintain their physical fitness levels, despite losing 3.9 ± 3.2 kg body mass during the pre- to mid-deployment phase 4. However, the extent to which energy deficits observed during this phase can be attributed to energy intake versus expenditure is not precisely known because of the following limitations: a) the authors measured energy expenditure during a representative 7-day period of military operations but not during the deployment to Afghanistan and; b) diet was assessed in 4-day periods of pre-, mid- and post- deployment using the self-report method of food diaries, where participants may have misreported intakes due to competing intense operational duties during their deployment 4.
A study conducted in 31 and 32 US Marines performing an artillery-training exercise in a desert climate (hot days and cool nights) (7 °C to 31 °C) found energy intakes of 2631 to 3050 kcal/day (66% and 65% of energy provided) to be below the energy expended (measured using DLW; 3953-4115 kcal/day, 61% or 77% of energy expenditure, respectively) in the study, with participants losing on average 1kg of body weight over 10 days 89 . Considering the average change in pre- to post-test in body weight was not significant even though energy expenditures averaged 4000 kcal/day, it is likely that misreporting bias may have occurred (e.g. misreporting by soldiers and/or misreporting bias by research personnel), as a combination of dietary assessment methods were used to assess intakes (participants used self-reported dietary log cards or food records to report food intake when consuming the MRE rations/beverages, whereas the visual estimation method was used to assess intake when participants consumed Unitized Group Rations (UGR) (both MRE and UGR were consumed each day; see Table 2.4 footnote for description of rations))89 . Although the investigators used the gold standard measurement of energy expenditure, the limitations identified in the dietary assessment methodologies may have contributed to measurement and systematic bias of dietary intakes; making it difficult to assess the weight loss attributed to an energy deficit. In addition, although intakes of vitamin A, vitamin C, thiamine, riboflavin, niacin, phosphorus, and iron were demonstrated to be at acceptable levels of MRDA; low intakes of calcium, magnesium, zinc, and folate were found. Participants were also consuming excess sodium (5239 mg/day).
Similarly, a study conducted by Tharion et al 36 , examined different types of ration consumption (‘T’ rations consumption in comparison to ‘B’ rations consumption; assessed using visual
30 estimation and food diaries) in US Marines performing low to moderate intensity physical activities in a hot climate 36 . The method of DLW was used to measure energy expenditure (3328 kcal/day). The authors found that marines on ‘T’ rations did not meet the Military Dietary Reference Intakes (MDRI; used for planning and assessing diets of US Military 98,99 ) for certain nutrients and consumed overall less energy (62% of the energy provided; 77% of the energy expended), carbohydrates, protein, dietary fiber, vitamin A, folate, thiamine, vitamin C, magnesium and phosphorus in comparison to marines on ‘B’ rations (69% of the energy provided; 86% of the energy expended) 36 . However, one of the major limitations of this study was the use of a combination of methods (visual estimation method and 24-hour food records) to assess intakes of foods, which consisted of MREs, B-/T-rations and non-ration food and beverages including alcohol 36 . Using the combination of methods to assess intakes could contribute to both measurement and systematic biases. Additionally, the intakes found in this study in relation to energy expended are not indicative of consumption of rations only (which is likely to be the case during field operations limited in availability of fresh foods/ on-site kitchen/safety). Participants lost on average 3 kg over 60 days, which is considered negligible in relation to physical performance. This loss is potentially attributed to water loss and/or heat acclimatization, where studies have shown that upon acclimatization, participants consume 25% less energy 58 . The difference in energy consumption of 18-36% from energy provided could be a result of a combination of under-reporting, heat acclimatization and methods of dietary assessment used in this study. This study also demonstrated that additional factors such as sensory (taste, palatability, smell, packaging, texture), individual preferences, variety and environmental/situational factors are likely to impact intake 36 .
2.7.2 Cold
Under cold environmental conditions, energy intake has been shown to be lower (ranging from 45%-77% of total energy expenditure) in comparison with energy intake in hot/temperate environmental conditions 34,91,100 . Limited studies have examined energy and nutrient intakes in extreme cold environmental conditions, possibly due to difficulties in obtaining accurate estimates of intakes under such austere conditions.
One of the earliest studies conducted in the cold environmental conditions was by Jacobs et al., in 1983 101 . This study demonstrated that soldiers consumed 86% and 69% of the energy in the rations provided (for two groups consuming standard rations and supplemented rations), which
31 was assessed using a combination of food waste and interview techniques 101 . Although this study used the best standard measures of assessing food intake, it did not provide data on energy expenditure, hence it is difficult to assess the magnitude of any energy deficit. Edwards et al., investigated intakes of military personnel on combat rations during winter evaluation exercises and found that participants consumed 61% of the energy of the total provided in the rations 100 . The authors found a significant decrease from pre- to post-body weight for all groups, which is likely a consequence of energy deficit. Investigators used a 24-hour dietary recall in combination with food waste to assess intakes, where misreporting bias was unlikely given the daily checks of the 24-hour dietary recall log and confirmation of the entries using food waste. However, the authors indicated that soldiers had difficulties in obtaining water and thus, considering that water intake is linked with food intake 5,55 , this may also have impacted energy intake and contributed to the observed energy deficits. These findings are similar to a more recent study that also used both food diaries and food waste to assess dietary intakes 34 . This latter study examined subsistence on combat rations by Norwegian soldiers participating in a metabolically demanding winter military training program 34 . Similar to the above study, the authors found severe energy deficits, where soldiers consumed only 66% of the total energy provided (47% of the energy expended; 57% in the Military Task Training group and 51% in the SKI (ski march) group) 34 . Daily checks of the food logs and confirmation of entries with food waste likely minimized misreporting bias, and the demonstrated energy deficit (difference in energy intake and expenditure measured using the doubly-labelled water) is likely a true consequence of study conditions (several factors including physical activity, experience of the soldiers and environmental conditions). However, this energy deficit was not translated into body weight loss, which the authors indicated was possibly due to the inaccuracies associated with measurements of clothed body weight 34 .
King et al., investigated intakes of US soldiers consuming two different Meal, Ready to Eat (MRE) field rations for lunch (Long Life Ration Packet vs. “T” Rations), and standard MREs for breakfast and dinners 91 . Using a combination of self-reported food records (lunch) and visual estimation methods (other meals), the study authors found adequate micronutrient intakes (except for Vitamin B6), high sodium intake, but inadequate energy intake (73%) in comparison to energy expenditure (measured using DLW), resulting in a significant body weight loss 91 . However, the recorded/observed energy intake which was on average 50% of total energy provided is likely due to misreporting bias as a consequence of using multiple
32 techniques to assess intakes as well as opportunities for soldiers to consume breakfast and dinner as part of a group (central distribution tents). Although, the authors 91 used the gold standard (DLW) in assessing energy expenditure, inaccuracies in their dietary assessment methods likely limited precise estimates of the magnitude of the energy deficit.
The majority of the studies conducted in non-Canadian military personnel during the temperate/hot (4 studies out of 6) and cold (2 study out of 4) conditions are dated and/or used self-reported and observational dietary assessment methods (jointly or in combination) to assess intakes (e.g. visual estimation methods and self-reported food records), which likely resulted in measurement bias (as a result of both respondent and researcher biases) 4,36,37,89,91,101 . Four out of 9 studies reported soldiers’ dietary intake as part of a group setting, which may have also contributed to misreporting bias 13,36,89,91 . Additionally, many of these studies assessed intakes from a combination of food sources (e.g. different types of rations including rations containing perishable/semi-perishable and fresh food items, personal foods and non-ration containing foods and beverages (including alcohol)), which makes it difficult to assess energy deficits attributable to field rations consumption only 4,36,89,91,100 . The sufficient consumption of macro- and micronutrients are also contingent upon the type of ration (e.g. specific food and beverage components) and the complete consumption of the provided ration. Researchers assessing intakes of different types of military rations have found energy consumption ranging from 64%-82% of the total provided, depending on the type of ration consumed (77% to 84% of energy expended) 36,89 . As shown by these studies, the trade and experience of a soldier likely influenced intakes and reporting of foods consumed as well, where special operations forces soldiers with experience tended to consume more food relative to their energy requirements compared to soldiers in training or with minimal experience (≤2 months). Several of the recent studies have used some of the best available methods of dietary assessment (i.e. measured food intake/food waste) to estimate intakes from standard military rations only, coupled with gold standard measurements of energy expenditure (DLW). Such studies that used accurate estimates of energy deficits, also found significant weight loss in soldiers (Table 2.4) 13,34 .
Overall, several studies conducted in non-Canadian military personnel indicated lower energy intake in comparison to the amount of energy expended coupled with weight loss during strenuous operations or training in the field. Although some information on adequate nutrient
33 intakes can be obtained from these studies, they may not be generalizable to the Canadian military population due to differences in demographics, training requirements, food environment, terrain/climate and standard operating procedures. Additionally, interpretation of these results requires a sound knowledge of the determinants of nutritional requirements specific to different types/duties of CAF military personnel.
Table 2.4: Summary of studies investigating energy intakes and energy expenditures in military personnel of other nations Sample (n) Location; Days Dietary Energy Type of Energy Energy Energy Micronutrients Weight (sex) reference temperature assessment expenditure Activities provided (EP) consumed Intake/Energy assessed loss (kg) method (EE) (kcal) in (EC) (kcal) Expended ¥ method; rations (% EP) & (kcal) (C/F/P) † US Special USA; 10 Visual DLW §; Low intensity Dining Facility 3585 (N/R) 99% N/M None Forces in Temperate/ estimation (3633) (N/R) (macronutrient training Hot method * % total energy n =11 (8.1°C to N/R) (males) 13 33.6 °C) US Special Measured DLW; High intensity MRE ** 2510 (64%) 48% 3.3 ± 1.9 Forces in food intake/ (5210) (3896) (macronutrient training food waste % total energy n = 9 N/R) (males) 13 16 Special USA; 28 Food diaries DLW; Low/high Vitamin A, D, Operations Temperate (similar to intensity E, C, Bs, soldiers (n=8 (-1°C to FFQ with MRE group MRE ** group 2782 (77%) 82% calcium, 1.1 ± 1.9 MRE, n=8 16 °C) pre-specified (~ 3400) (~3600) 45/38/16 phosphorus, MRE- portions) MRE- MRE- 1946 (97%) 61% magnesium, 4.3 ± 0.7 restricted) restricted restricted ** 40/46/13 zinc, iron, (males) 14,30 group group sodium, (~ 3200) (~2000) Special Panama; 10 N/R N/R Low/high Rations 3301 (94%) N/M Vitamin Bs, 5.5 Operations Hot intensity (~3500) 64/15/21 sodium, kg/man soldiers (30°C to potassium, (estimate n=19 34 °C) calcium, d from (males) 37 magnesium 292g/man /day) Royal Afghanistan; 4 Food diary DLW; Low/ moderate/ Combat Rations 2531 (62%) 70% Micronutrient 3.9 ± 3.2 Marines Hot (3626) high intensity (4097) + (macronutrient status assessed n=64 (Temp N/R) personal foods % total energy using (sex N/R) 4 N/R) urinary/blood biomarkers US Marines USA; 10 Dietary log DLW; Light/high Vitamin Bs, n=31 Temperate/ cards + (EE range intensity potassium, iron, (males) 89 Hot visual 3953 – 4115) magnesium, (7.3°C to estimation zinc, calcium,
34 35
31 °C) method 4341 2 Unitized 2631 (66%) 61% phosphorus and 1.0 ± 1.7 Group Rations 48/37/16 sodium (UGR) (A/B/T rations) + 1 MRE ** (4000) US Marines 3950 UGR (4000) + 3050 (65%) 77% n=32 8% CHO drink 61/28/12 (males) 89 (708) US Marines Bahamas 60 Visual DLW; High intensity 2 T-Ration Data presented 77% Vitamin A, C, E, 3.1 ± 3.7 (n=17) Islands; estimation (3328) (2840) ** + 1 for test period B-vitamins, (females/ Hot method + MRE (~1300) + 3 only folate, calcium, males) 36 (23.4 to 24h food personal foods 2572 (62%) phosphorus, 29.8°C) ‡ records 47/36/16 sodium, iron, US Marines Light/moderate 2 B-Ration 2866 (69%) 86% potassium, (n=34) intensity (2860) ** + 1 50/34/14 magnesium, zinc (females/ MRE (~1300) + males) 36 personal foods Soldiers N/R; 4.5 Measured N/M Varying Rations (N/R) 3350 (86%) N/M N/M N/M n=16 Cold food intake/ intensities (3880) 55/35/11 (N/R) 101 (-5°C to food waste + Rations (N/R) 3721 (69%) N/M -25 °C) interview (5420) 64/27/10 US soldiers Alaska; 10 Self-reported Energy Training MRE Rations ** 2633 (61%) N/M (sex N/R) Cold 24h food log expenditure exercise 48/34/18 (127) 100 (-42 °C to confirmed not measured 2°C) with but based on Group 1 measured cold weather 4 MRE VI 2024 (42%) Estimated as 2.1 ± 2.0 (n=32) food intake / requirements (4816) 42/42/17 45% Group 2 waste (~4500) 3.5 MRE VIII 2810 (61%) Estimated as 1.6 ± 2.0 (n=31) (4571) 47/38/16 62% Group 3 3 MRE VI + 2841 (65%) Estimated as 1.5 ± 2.7 (n=30) supplemental 45/39/17 63% pack (4325) Group 4 3 MRE VIII + 3562 (76%) Estimated as 1.5 ± 1.8 (n=34) supplemental 50/35/15 79% pack (4658) Norwegian N/R; 4 Self-reported DLW; Garrison-based 3 rations per 3098 (82%) 57% N/M 1.8 ± 1.0 soldiers Cold food logs (5480) training day (~3800) 47/36/17 n=21 (-6.2 °C to 3 (24h) DLW; Ski march 4 rations per 3461 (66%) 51% No (males) 34 -26 °C) confirmed (6851) day (~5100) 45/36/16 change with measured food intake /
36
waste
US soldiers Alaska; 10 Diet logs + DLW; Minimum MRE-T Rations Thiamin, n=96 (males) Cold visual (4253) information on Breakfast/ riboflavin, 91 (-8°C to estimation activities; Dinner (both niacin, B6, -38 °C) method Training Batteries A and calcium, exercise B) phosphorus, magnesium, Lunch (Long 3035 (52%) 71% iron, sodium 1.06 ± 1.0 Battery A Life Ration 50/36/15 (n=45) Packet) 5800 Battery B Lunch (MRE-T) 3271 (57%) 77% 1.97 ± 0.4 (n=51) 5700 46/38/16 *Visual Estimation Method is a procedure where a trained technician or data collector records the food items and visually compares portion sizes of the participants’ food to the measured standards, where weighed portions of each food item serves as a standard portion 21 ; ** MRE=Meal, Ready to Eat, MRE VI and VII are rations with different amounts of energy and individual food components; MRE Rations differ in the amount of energy as well as in the reheating method, where ‘B’ rations contain canned, dried foods that require trained cooks to prepare, whereas ‘T’ rations only require reheating, Unitized Group Ration is a combination of A, B and T-MREs (for further information on MREs, see US military studies 36,89,100 ); †Carbohydrates/Fat/Protein as % of total energy consumed; ‡Considered hot by the investigators; §Doubly-labelled water; EE = Energy Expenditure; EP= Energy Provided in rations; EC = Energy Consumed; %EP = Energy consumed as % of energy provided (from amount in EP from rations/MREs only and not personal/local foods unless otherwise indicated); ¥EI/EE = Energy intake as % energy expended where estimated (calculation based on indirect measures of EE) and/or measured is from the energy expenditure reported by investigators in their studies; N/R = Not reported; N/M = Not measured.
2.8 Section Summary and Rationale
Generally, there is paucity of data accurately assessing consumption of field rations in relation to precisely measured energy expenditure in CAF military members. Additionally, studies conducted in extreme environmental conditions present challenges in assessing intakes, thus most researchers have used self-report methods of dietary assessments, which are prone to misreporting bias. In addition, those studies that accurately measured dietary intakes did not use precise measurements of energy expenditure (such as DLW), therefore limiting our ability to accurately assess energy deficits.
In summary, assessments of the habitual dietary intakes and energy deficits of CAF personnel consuming field rations are lacking, with evidence gaps in the literature, especially in view of recent changes in CAF demographics, advances in technology/ equipment and anticipated CAF operating scenarios. Therefore, Part 1 of this thesis addresses these concerns by first assessing the ad libitum consumption of field rations under thermo-neutral conditions compared with the habitual dietary intakes of CAF personnel. Second, this thesis will assess the ad libitum consumption of field rations under extreme environmental temperatures and strenuous physical activity levels in an experimental trial conducted in an environmental chamber and during a winter weather field training exercise.
2.8.1 Addressing Links to Part 2
Most of the studies conducted thus far in CAF personnel to assess dietary intakes have used self-reported dietary techniques, which are prone to misreporting and are difficult to conduct in the field. Quantifying the energy balance in CAF personnel requires an accurate assessment of energy expenditures and requirements, which prompted consideration of other novel mobile dietary assessment methodologies available for such a task (discussed in Part 2, Chapter 3). As a result, this thesis also evaluated a novel tablet application to assess dietary intakes in relation to the current gold standard in dietary assessment methodology (that of the measured food intake /food waste collection).
37
Chapter 3 Background and Literature Review
Part 2: Dietary Assessment Methodologies
Dietary assessment refers to assessing food consumption at the national level (e.g. food supply/production), at the household level and at an individual level 102 . This section discusses both the traditional methods and novel mobile technological innovations in assessing dietary intakes of individuals only. For the purposes of this thesis, traditional dietary assessment methodologies refer to methods that are typically used to record diets at the individual level using paper and pen/pencil surveys and measured food intake/food waste methods, whereas novel mobile techniques in dietary assessment methodologies are defined as computerized and/or digital methods of recording dietary intakes. Assessing accurate dietary intake information in field operations for military personnel is challenging due to the logistics of carrying out food surveys in such austere and physically demanding conditions.
3.1 Types of Traditional Dietary Assessment Methodologies
3.1.1 Measured Food Intake/Food Waste
The method of assessing diets through measured food intake/food waste requires researchers to measure all food taken and participants to provide research coordinators with the contents of all non-consumed, partially consumed and leftover food/beverage items. This method allows for the accurate assessment of total food intake and waste and hence, is considered the gold standard where the researcher is able to both observe and measure the food provided and consumed 96 . It also involves accurate weighing of portion sizes and minimizes both respondent and researcher bias. Thus, this is a costly and time-consuming method, which can be intrusive on the participants and onerous on the researcher, as they have to sort and weigh all the provided and non-consumed, partially consumed and leftover food/beverage items 103 .
38 39 3.1.2 Visual Estimation Method
The technique of visual estimation requires a trained technician to record the food items and visually compare the portion sizes of the participants’ consumed foods to the measured standards (weighed portions of each complete food item served as a standard portion) 21 . This method requires direct observation from trained personnel, which can be labor-intensive, prone to researcher bias and the accuracy of the estimates depends upon both the type and the variety of food consumed and skills of the technician 95 . Although studies evaluating validity of the use of visual estimation method have shown variability in accurate assessments of energy and nutrient intakes 104-106 , this method overcomes some of the limitations of intrusiveness, memory bias and respondent bias found in methods food diaries and food recalls.
3.1.3 Food Records/ Food Diaries
In the food records approach, the respondent is asked to record, at the time of consumption, all foods and beverages consumed over a specified number of days 96 . The amounts consumed are measured by standard household measures (e.g. cups/tablespoons or food scale) and/or estimated (using models, pictures). Typically, food records are collected for 3-7 consecutive days and include both week-days/weekends. The food record method, especially when foods are weighed and recorded for several days, is often considered an imperfect gold standard in quantitatively assessing information on food consumed 102 . However, limitations of this method include respondent bias where responders may under- or over- report consumption of certain food items 107 . It is burdensome for the participants as they may find the task of keeping a detailed track of consumed foods/beverages demanding. Research coordinators also have to train the participants in keeping records to ensure accurate data collection and participants may find the process of manually entering and coding the foods in the diaries burdensome. This method is expensive and thus cannot be used in large studies 102 .
3.1.4 24-hour Dietary Recall
In the 24-hour dietary recall (24hr recall) method, respondents are asked by a trained interviewer, to remember and report all food and beverage items consumed in the preceding 24 hours 102 . The recall can be conducted in person or by telephone interview or online 102 .
Advantages of the 24hr recall method include the following:
40 • It doesn’t require respondent literacy because the tool itself and responses are captured by the interviewer; • The tool is relatively less burdensome on the respondent as they are not required to weigh or write down food items; • It allows for detailed capturing of the foods consumed as interviewers are trained to probe the respondent for necessary details, which are often forgotten by respondents when filling out a food record (e.g. food preparation and/or addition of condiments) • Most 24hr recall methods use computer assisted techniques with computer assisted prompts for the interviewer to ensure completeness and; • The tool has less potential to interfere with the dietary behaviour of the respondent as the recall occurs right after the consumption of the food.
However, the main disadvantage of this method is memory bias, where respondents may not accurately remember all the food/beverages consumed 102 . Although the method assesses the actual intake of an individual, a single 24-hour dietary recall is often not sufficient to describe an individual’s usual intake, thus multiple 24-hr recalls on the same individual are required 96 .
3.1.5 Food-Frequency Questionnaires
The food frequency questionnaire (FFQ) assesses the usual frequency of consumption of each food from a list of common pre-determined food items over a specified period of time (e.g. one week or one month) 102 . Some questionnaires incorporate portion sizes of the item consumed and thus are referred to as semi-quantitative food frequency questionnaires (sq-FFQ). There are many FFQs available and the use of a particular FFQ depends on the validation of the instrument for the use and particular population in question. However, the design of an FFQ involves an extensive food list (closed versus open-ended), appropriate length, portion size, and seasonality of food items and time frame of the captured foods. Major strengths of the FFQ are that it is inexpensive to administer and process and thus can be used for large epidemiological studies. In addition, it is usually self-administered and can be completed within 30-60 minutes. However, FFQ are prone to measurement error since many details (e.g. methods of cooking and mixed meal ingredients) are often missed and the quantification of intake is limited, in comparison with intake captured by recalls or records 102 .
41 3.2 Technological Innovations in Dietary Assessment Methods
Dietary assessment methods have traditionally relied on tools such as 24hr recall, FFQ or multi- day weighed food records (e.g. 3 Day weighed food record (3DwFR)) 108 . As discussed in Section 3.1, data collection using such methods is prone to measurement errors including recall bias, costly processing, respondent burden, and the researcher burden of coding recorded foods 109 . Moreover, using manual methods of collection restricts an individual’s ability to understand their food consumption patterns and nutrient intakes and limits the quick and easy analysis of dietary habits at the population level, which can hamper the development of frameworks for consumer support regarding food and dietary habits. This also applies in a military setting where precise methods of quantifying dietary intakes are required for both field-based researchers and health professionals (e.g. physicians and dietitians) to provide evidence-based interventions and recommendations on optimal nutritional practices for military personnel. However, collection of accurate dietary intake data from military personnel is challenging in the field with a high prevalence of underreporting due to physical and cognitive stressors such as temperature extremes, scheduling of operations, consumption of unauthorized foods and beverages, sleep deprivation and heavy load carriage 2,11,19,31,110 .
Considering recent advancements and increases in adopting smart-phone technology, the use of tools such as mobile apps and dietary trackers, and image capturing equipment may overcome some of the barriers associated with traditional dietary assessment methods 109 and be particularly useful for military personnel in the field.
Our research investigating the assessments of dietary intakes of CAF personnel under thermally neutral and extreme environmental conditions gave us an opportunity to evaluate emerging technology for assessing diets in comparison with traditional dietary assessment methods.
3.2.1 Mobile Application Technology as a Method of Dietary Assessment
The development of smart phones has led to a proliferation of software applications (apps) that may potentially reduce the costs of collecting and recording data as well as allow for real-time capture of consumed foods 111 . There are several commercial mobile apps (e.g. MyFitnessPal and Lose It!) that facilitate digital recording of dietary intakes 112,113 . However, studies conducted thus far have mostly focused on investigating the effectiveness of these apps in
42 promoting health and/or weight loss and those that validated a mobile app for assessing diets have mostly used personal digital assistants (PDA) 112-114 . Importantly, limited data exist on the validation of these commercial mobile apps against the current gold standard for assessing dietary intakes and/or reference recovery biomarkers to assess their accuracy and reliability 115,116 .
3.2.2 Relevant Literature Review
Although research assessing the use of commercial mobile apps in military personnel, especially CAF, is lacking; several small-scale studies have been conducted to validate, evaluate and assess the usability of mobile phone apps in capturing dietary intake data in different age groups and diverse populations. The studies in this literature review (up to 2016) include those, which used a mobile device nutrition app to record dietary intakes and included outcome measures associated with its use. Studies of diseased or high-risk populations are excluded here; as such results are (likely) not relevant or generalizable to Canadian military or general healthy populations. Studies of nutritional interventions for weight loss etc. are also excluded; as such results are not relevant to the proposed research thesis.
Dietary Assessment Validation Studies:
A number of studies have tested an app’s ability to capture dietary intake variables in comparison with traditional dietary assessment methods. Apps were categorized as either data- based or photography-based. Most studies used a personal digital assistant (PDAs) except for one study, which utilized a mobile phone/tablet.
Data-based applications:
Eight different apps were tested in fourteen studies. These apps were designed for users to scroll or search for food items from a database (e.g. USDA National Nutrient Database for Standard Reference) and enter the portion size of the amount consumed. Professionals received the information electronically (e.g. by uploading data to computers or by email) and data did not have to be manually entered. Users were usually provided with feedback instantly.
A PDA was provided to 39 healthy participants to record their dietary intake for 3 days 117 , followed by a 24hr recall with a weighed lab lunch. The authors found that the PDA captured
43 energy and macronutrient intakes with a moderate to good agreement compared to a 24hr recall interview (Pearson correlation range: 0.5 to 0.8). In a follow-up trial in which 174 overweight/obese participants were randomized to either paper or PDA food diaries, nutrient intakes of these two methods were compared with those obtained with a 24hr recall interview (at the end of the study) 118 . Spearman correlations were significant for measured nutrients (energy, macronutrients, cholesterol, fibre, Vitamin A, Vitamin C, calcium and iron) between both PDA (r range: 0.4 to 0.7) or the paper-based food diary (r range: 0.6 to 0.8) and the 24hr recall. However, these investigators found that 49% of error associated with intake using the PDAs in comparison with the laboratory weighed lunch was due to improper portion size estimation 117 . In comparison, Fukuo et al., 119 incorporated the use of food photographs with the PDA to help with portion size estimation and found no significant differences between energy and macronutrients measured using a PDA and a 24hr recall for the same day (Pearson correlation range: 0.7-0.9).
Two studies measured total energy expenditure (TEE) for validating a PDA dietary assessment software program. In overweight individuals, similar rates of energy under-reporting were found in both PDA and conventional methods based on equation estimated TEE using Goldberg’s cut- off 120 . Using the gold standard doubly-labelled water (DLW) technique for measuring TEE, McClung et al. 110 found TEE to be correlated with the PDA (Pearson correlation: 0.6) but not between the TEE and the energy intake recorded on paper, supporting the superiority of the PDA method. These studies, however, were lacking randomized designs for validating the smart-phone app, and most did not use reference recovery biomarkers and/or current gold standard dietary assessment methods in a healthy population.
Photography-based applications:
Two different types of photography apps 121-124 required users to image capture food items before and after consumption using set techniques and criteria. Users had the ability to document details not visible on images (e.g. mixed items). The photos were uploaded at study visits or via phone networks and were compared with photos of standardized portions of weighed foods.
Energy and macronutrient intakes estimated for one day from a photography app (Wellnavi) were compared with a weighed food record for the same day in 48 female nutrition students.
44 Fair to good Spearman correlations were found for several micronutrients (r range: 0.5 to 0.8) 121,122 . In comparison, correlations were found to be lower though significant (r range: 0.5 to 0.6; p≤0.05), when Wellnavi was administered in 75 healthy adults from the general population during a five-day study 123 .
In another study, a photography-based app had high correlations of estimated energy intake with the weighed energy intake (r:0.9) 124 . However, studies validating a photography-based app with known gold standards of energy intake and expenditure are lacking.
Both data and photography apps were reported to have moderate to good correlations of nutrient intakes in comparison with traditional dietary assessment methods 111 . Moreover, user satisfaction with data-based and photography apps have been generally high, although minor issues such as improper device use, difficulty finding specific food items in the databases and poor photographic techniques/lighting have been reported 111 .
3.3 Section Summary and Rationale
Although there are many commercial mobile apps that may be used for recording dietary intakes, few of these have been validated for dietary assessment and none have been used to examine the dietary intakes of CAF or other military personnel.
Several limitations are evident from the literature review: 1) Most of the studies used a PDA with only two studies employing a mobile phone; 2) Validation studies conducted thus far are lacking in randomized designs and few have used either the gold standard dietary assessment method or validated recovery reference biomarkers; 3) Most trials have studied the app in highly motivated weight-loss participants and very few in healthy people, with no information on the applicability of these apps in users versus non-users of smart-phones; 4) Most studies have provided participants with feedback dietary information that may influence the validity of methods; and 5) There are no studies conducted in CAF or other military personnel, using an available commercial application and Canadian-specific food composition data to assess habitual dietary intakes and for nutritional composition of field rations. Therefore, in part 2 of this thesis, we leveraged this research to validate a commercial mobile app, MyFitnessPal (which was selected because it allows the addition of nutritional composition information of combat rations) with energy intake in CAF personnel, assessed using gold standard measured
45 food intake/ food waste method and reference recovery biomarkers. This enabled us to validate the app in a highly compliant, well-characterized dietary environment against gold standard dietary assessment techniques.
46
Chapter 4
Overall Summary and Research Gaps
Adequate nutrition is critical for sustaining physical health and mental performance, thus contributing to the operational readiness of a soldier. To date, assessments of the habitual dietary intakes of CAF military personnel are lacking and are required in order to provide nutritional strategies for optimal training and operational readiness prior to mission deployments.
Field rations are food allotments typically supplied during deployment and training. Although, these rations are intended to be nutritionally sufficient for standard military operations, the DRIs used in the development of these rations may not adequately consider some of the strenuous operational tasks that military personnel are required to execute during deployments. Additionally, there may be increased requirements for specific micronutrients (e.g. sodium and iron) as a result of physiological adaptations under conditions of environmental stress 19,60,125 . To date, there is limited research on dietary adequacy with the consumption of rations, specifically micronutrient intakes, in CAF personnel under temperate and/or extreme temperatures and strenuous physical activity conditions. During extreme temperature conditions, field rations can be supplemented with incremental allowances, although their provision is at the discretion of unit commanders’ authorization to allocate additional financial resources. Thus, there is no empirical basis for the provision of these incremental allowances under conditions of extreme environmental stress, based on energy expenditure, calibrated for temperature and physical activity levels.
During deployment, military personnel have been documented to exhibit a negative energy balance, where energy intakes are significantly reduced in the field (e.g. in metabolically challenging training and operations) leading to energy deficits of 500 to >6000 kcal/day 5,13,17,34 . Research has indicated that military personnel exhibit voluntary anorexia by consistently under- consuming food regardless of the amount provided and/or available for the missions 2,5,100 . Many factors have been proposed as contributing to voluntary anorexia including the palatability or ease of preparation of food, environmental temperatures, operational tempo and individual motivational/biological rhythms 2,5 . Several studies have reported on the negative
47 physiological and psychological consequences of voluntary anorexia. Although several studies in military personnel from other nations have demonstrated suboptimal consumption as a result of extreme environmental conditions combined with physical and cognitive stressors, there is a paucity of data in this regard on the impact of adequate ration provision on nutrient intakes under extreme climatic condition (e.g. winter weather field setting) in CAF personnel. The majority of the studies conducted with Canadian military personnel did not accurately assess energy and nutrient intakes along with accurate measures of energy expenditure. For example, some used self-reported dietary assessment methods, which are associated with misreporting bias while very few accurately measured energy expenditure 9,17,18 . Therefore, it is difficult to assess the extent to which energy deficits observed during field operations can be attributed to energy intake/expenditure. Observations on the impact of consumption of field rations on dietary intakes should also be supplemented with a better understanding of the changes in nutritional biomarkers (that may occur as a result of consuming field rations). Nutritional biomarkers act as indices of physiological or biological responses, which can then impact performance. However, assessments of potential changes in nutritional biomarker indices in military personnel as a result of acute exposure to environmental extremes while consuming field rations are limited. In addition, it is likely that the impact of stress from both physical and psychological events surrounding military operations on dietary intakes may vary between sexes, however, no study thus far, in CAF military members, has explored the different considerations between male and female nutrition 2.
The limited data available on assessments of dietary intakes in CAF personnel can partially be attributed to the challenges of assessing intakes in this population. Studies conducted to date have used traditional dietary assessment methodologies (e.g. food diaries), which are difficult to carry out under field conditions and prone to measurement errors. Thus, research examining novel techniques for assessing dietary intakes in this population are warranted.
48
Chapter 5
Scope, Objectives and Hypotheses of Thesis
5.1 Scope and Objectives
This thesis was designed to generate data, in a convenience sample of CAF personnel, on energy and nutrient intakes from; (i) their habitual diets at home, (ii) while consuming ad libitum field rations at home, and (iii) under operational stress augmented by extreme environmental temperatures and demanding physical activities. This sample was not selected with the view of being representative of the CAF population. The habitual dietary intakes of CAF personnel are unknown; although these are important as they can contribute to the overall physical fitness and operational readiness of a solider for missions that can occur at any time.
Limited research that exists on quantifying the consumption of field rations under conditions of environmental stress in CAF personnel is dated, with evident gaps in the literature. Studies conducted in CAF personnel have not fully profiled nutrient intakes, specifically micronutrient intakes, and used a variety of self-reported dietary assessment methodologies that were not systematically monitored. Additionally, studies did not use accurate/precise methods of energy expenditure in combination with gold standard dietary assessment methods, and as such, the extent to which energy deficits can be quantified and attributed to energy intake and expenditure is unknown in CAF personnel operating or training in temperature extremes. Furthermore, there is paucity of research on assessment of recovery biomarkers in relation to ration consumption and under periods of extreme environmental temperature stress in CAF personnel. Additionally, research has mostly focused on the nutrient considerations of male military personnel with limited data available for females in military.
Thus, the overall objectives of this thesis were, in several convenience samples of CAF personnel, to: 1) Assess their habitual dietary intakes at home in comparison with the MDRIs 2) Evaluate energy and nutrient intakes when consuming field rations under ad libitum conditions at home, in comparison with MDRIs and habitual dietary intakes
49 3) Measure dietary intakes when consuming field rations in an experimental laboratory setting in a carefully controlled temperature and humidity chamber (e.g. temperate, hot and cold) while engaged in a standardized set of physically demanding activities 4) Determine dietary intakes when consuming field rations in a winter weather field training exercise during a CAF training course 5) Validate the use of a novel technology in assessing dietary intakes of CAF personnel consuming field rations at home
This thesis also addresses additional sub-objectives: 6) Examine the levels of nutrient-related biomarkers in relation to ration consumption and ambient temperature extremes 7) Explore the nutrient intakes of male and female CAF military personnel (with Objective 4 above)
5.2 Specific Hypotheses
We hypothesized that, in several convenience samples of CAF personnel: 1) Habitual dietary intakes will be similar to that of a healthy Canadian adult population but are not likely to meet the recommended intakes for optimal performance or meet the high-energy demands sometimes required of military population (CAF personnel) 2) Field rations (IMPs) provide sufficient energy and macronutrient intakes but CAF personnel will not eat enough due to the palatability of the rations and may not eat the appropriate combination of food and beverage products in order to meet their micronutrient intake requirements 3) Energy intakes between different environmental conditions in the laboratory trial in combination with physically demanding activities will be low compared to energy expenditure 4) The impact of environmental stress during an extreme cold winter field exercise combined with physical and cognitive stressors during concurrent training in this environment will lead to a substantial energy deficit 5) The use of commonly best available technologies, such as a tablet application, can be used to accurately assess dietary intakes of CAF personnel consuming rations
Our hypotheses for the sub-objectives (exploratory) are as follows:
50 6) Acute periods of consuming field rations will not impact nutrient-related biomarker concentrations but the combined effect of operating strenuously under environmental stress may induce changes in specific biomarkers 7) Although males and females will require similar amounts of energy and macronutrients during field operations/training, it is likely that female soldiers may exhibit less than recommended intakes of some micronutrients (e.g. iron/calcium).
5.3 Preview of Chapters 6-9
Objectives 1-3 & 5-6 were carried out in a convenience sample of 18 CAF personnel who were Regular Force or Class A Reservists, participating in a laboratory metabolism and feeding study (May 2014 to June 2015). Objectives 4 & 7 were examined in a convenience group of Army Reservists completing a basic military qualification-training course at Canadian Forces Base (CFB) Meaford during January 24 th -January 30 th , 2015.
Objectives 1 and 2 were examined in Chapter 6, where CAF personnel reported their habitual dietary intakes and ad libitum intakes from field rations under temperate conditions at home. In this study, participants used the weighed food record to record their habitual dietary intakes. For the purposes of recording intakes from field rations, participants were randomized to either a weighed food record or a tablet app (which included information on the nutrition composition data of rations). Measured food intake/food waste method was also used to acquire accurate information on ad libitum intake of rations under temperate conditions at home. Participants’ energy and nutrient intakes were compared between ad libitum consumption of rations with their habitual diets at home and their macronutrient and micronutrient intakes from both field rations and habitual diets were assessed with MDRIs.
Objectives 3 and 6 were examined in Chapter 7, where CAF personnel consumed rations only in a laboratory metabolism and feeding study and were randomized to four treatments defined as follows: 1) sedentary (temperate / 21 °C); and during 8-hours (2-hours alternating activity and rest) of a range of operational like physical activities (light to strenuous) in an environmental chamber controlled at; 2) hot (30 °C), 3) cold (-10 °C) and 4) temperate (21 °C). Participants’ energy, macronutrient and micronutrient intakes were compared across these four treatments. Additionally, data on blood and urinary biomarkers were assessed in order to explore the acute impact of ration consumption and environmental stress on concentrations of biomarkers.
51 Objectives 4 and 7 were examined in Chapter 8, where participants were completing a CAF- mandated basic military qualification training course (5 days in the field during winter). In this winter weather field training exercise, intake was confined to field rations only, measured using the food intake/food waste method. Additionally, as we had equal number of males and females participants, we were able to examine the impact of environmental stress in combination with physical and cognitive stressors on the dietary intakes of the sexes as exploratory analyses (this study was not powered to detect differences between the sexes).
Objective 5 was examined in Chapter 9 where we validated a tablet app for assessing dietary intakes of CAF personnel on combat/field rations. In this study, data from the CAF participants consuming ad libitum rations under temperate conditions at home were used. Results were also compared with reference recovery biomarker data.
Thus, Chapters 6-8 were designed to address Part 1 of this thesis by focusing on assessments of energy and nutrient intakes of CAF personnel before and during deployments, whereas Chapter 9 deals with Part 2 of this thesis regarding the assessment of novel methods for assessing dietary intakes in military personnel. Together, these four studies assess dietary intakes in a convenience samples of CAF personnel under: 1) habitual at home conditions; 2) at home ad libitum consumption of field rations; 3) varied environmental treatments in combination with physically demanding typical military tasks in a laboratory setting; 4) winter weather field feeding; and 5) support the use of novel methods for assessments of dietary intakes in CAF military members.
52
Figure 3.1: Summary of Chapters 6, 7, 8 and 9
53
Chapter 6
Dietary Intakes from Canadian Armed Forces Ad Libitum Consumption of Field Rations Compared to Soldier’s Home Dietary Intakes (and Military Dietary Reference Intakes)
This study is under review with co-authors.
This study addressed objective #1 and # 2 of my thesis, to: compare, in a convenience sample of Canadian Armed Forces (CAF) military members, their ad libitum nutrient intakes from self- selected field rations to their habitual at home dietary intakes, and to assess both with Military Dietary Reference Intake (MDRIs) recommendations. This study was part of a larger randomized experimental trial quantifying the impact of harsh environmental temperatures and strenuous physical activity on energy intake (this thesis) and expenditure (Mandic et al., energy expenditure data (unpublished) 126 ) in a convenience sample of CAF military personnel (Chapter 7).
Student’s contribution:
The original idea for this study and its design were mine. I was involved in developing the experimental protocol for this study in collaboration with Iva Mandic, Dr. Len Goodman, Dr. Ira Jacobs and my supervisor, Dr. Mary L’Abbé. I conducted the study (in collaboration with Iva Mandic), and collected, entered and analyzed the data (dietary intakes). I independently learned the data analysis and prepared a draft of the manuscript prior to engaging my co-authors in reviewing and revising the manuscript for subsequent publication.
54 Dietary Intakes from Canadian Armed Forces Ad Libitum Consumption of Field Rations Compared to Soldiers’ Habitual Home Dietary Intakes (and Military Dietary Reference Intakes)
Mavra Ahmed 1, Iva Mandic 2, Len Goodman 3, Ira Jacobs 2, Mary L’Abbé 1
1 Department of Nutritional Sciences, University of Toronto, Toronto, M5S 3E2, Canada; [email protected] (M.A.); [email protected] (M.L.) 2 Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, M5S 2W6, Canada; [email protected] (I.M.); [email protected] (I.J.) 3 Defence Research and Development Canada – Toronto Research Centre, Toronto, M3K 2C9, Canada; [email protected]
Key Words: dietary intakes, diet assessments, military, nutrition
6.1 Abstract
Background: Sufficient energy and macro-/micronutrient intakes is a major contributor to optimal performance and health in the military but metabolically challenging operations and training conditions often result in a gap between consumption and the amount of energy provided in field rations. Factors such as palatability and quality/quantity of field rations can further compound this challenge and potentially lead to reduced energy intake, contributing to a negative energy balance. Although, field rations are intended to be nutritionally sufficient for standard military operations, limited data exist on the habitual home diets of CAF personnel and on the ad libitum intakes of nutrients, specifically micronutrients, from field ration consumption.
Objective: The objective of this study was to compare, in a convenience sample of CAF members, their ad libitum nutrient intakes from self-selected field rations at home with their intakes from their habitual home diets, and to compare both with Military Dietary Reference Intake (MDRIs) recommendations.
Design/Statistical Analyses: 18 CAF participants randomized to either a weighed food record or a tablet application recorded their dietary intake from ad libitum consumption of field rations. To record habitual home diets, participants used a weighed food record. Paired student’s t-test or Wilcoxon matched paired test was used to compare nutrient intake levels between home diets
55 and field rations.
Results: Energy intakes were similar between ad libitum intakes from field rations (2688 kcal) and observed home diets (2657 kcal), although participants had significantly higher intake of protein and fat from their home diets and higher intake of carbohydrates from the field rations (p≤0.05). The sample of CAF personnel in this study demonstrated less than recommended intakes of some micronutrients (vitamin A, vitamin D, folate, calcium, magnesium and potassium) both from their home diets and from self-selected field rations. In contrast, participants had adequate intakes of vitamin C and iron whereas sodium intake was higher than the DRI upper limit when consuming home and field ration diets.
Conclusion: Data do not support reduced energy intake due to ration palatability in an acute setting, as there were no differences in energy intake between ad libitum consumption of field rations compared with home diets. Compared with MDRI recommendations, CAF personnel had less than recommended intakes of some micronutrients from rations and from home diets. These results may warrant further investigation into optimal ways to ensure sufficient micronutrient intakes, particularly when field rations are consumed for extended periods of time.
6.2 Introduction
Military personnel are at an increased risk of insufficient energy and nutrient intakes as they are exposed to physical and cognitive stressors during metabolically challenging training and operations 1,2 . It is well established that insufficient energy and nutrient intakes can contribute to injury, prolong recovery time, may depress immune function and can have negative psychological and physiological consequences 5,14,16,25 . Therefore, adequate dietary intake is a major contributor to the military’s optimal performance and health 26,27 .
Dietary choices and behaviours, including the preference in foods consumed on a routine basis, can impact physical/cognitive performance, sleep and overall health 27 . Assessing the habitual at home dietary intakes of Canadian Armed Forces (CAF) personnel can help determine their overall nutritional status as well as provide information on preferred food items and habitual intakes of nutrients. This information is relevant for planning, monitoring and assessing nutrition interventions (e.g. for developing food intake guidelines for military personnel) in order to optimize both mental and physical performance. Assessment of the habitual at home
56 dietary intakes of CAF personnel is unknown. However, those conducted in the United States (US) military personnel have indicated suboptimal nutrient status with lower than recommended intakes of fruits, vegetables and whole grains 22,28 . Similarly, a study conducted in Thai Active Duty Army Personnel demonstrated suboptimal nutrient intakes 29 in relation to their recommended intakes.
Dietary Reference Intakes (DRIs) are the national nutrient requirements designed for the healthy Canadian adult population 80 . They are also used to guide the nutrient composition of the CAF field/combat rations or Individual Meal Packs (IMPs) 11 . Although these rations are intended to be nutritionally sufficient for standard military operations, the DRIs may not adequately consider some of the strenuous and demanding tasks that military personnel encounter during training and/or combat 11 . The US Military Dietary Reference Intakes (MDRIs) are established for planning and assessing diets of military personnel 98,99 . The MDRIs for macronutrients and micronutrients are adjusted to take into account the intense activity and increasing metabolic demands of military personnel while operating or training in the field 98,99 .
Soldiers need to consume sufficient energy and nutrients in order to adapt to the metabolically challenging operations and training conditions as arduous conditions experienced during operations or training often result in a gap between consumption and the requirements needed for optimal performance 15 . Factors such as palatability, quantity and variety of field rations, meal timing, ease of access to food and time to prepare can further compound the challenge of gap between the amount of field rations provided in relation to the amount consumed 2. A number of Canadian studies have assessed energy and nutrient intakes from field rations in relation to energy expenditures under arduous conditions in operational settings, but none were designed to assess whether factors such as those identified above may play a role in contributing to insufficient intakes 9,17,18 . Therefore, in CAF personnel, ad libitum intakes of energy and nutrients, specifically micronutrients, from field ration consumption under non-operational settings are unknown.
6.3 Objective
The primary objective of this study was to compare, in a convenience sample of CAF members, their ad libitum nutrient intakes from self-selected field rations to their habitual home diets. The secondary objective was to compare their intakes from self-selected field rations and habitual
57 diets with MDRI recommendations.
6.4 Methods
6.4.1 Study Participants
This is an observational study in a convenience sample of 18 CAF personnel who were Regular Force or Class A Reservists. This study was part of a randomized experimental trial, which was conducted in collaboration with the Faculty of Kinesiology and Physical Education, University of Toronto and under a research contract with Defence Research and Development Canada (DRDC), to quantify the impact of harsh environmental temperature and strenuous physical activity on energy intake and expenditure in a sample of CAF military personnel. A detailed description of the study and the experimental trial can be found in the technical report prepared by University of Toronto for DRDC 126 . A total of 27 participants initially volunteered for the study. Two participants never started the protocol and an additional 7 participants dropped out due to scheduling difficulties and/or non-compliance due to the demanding nature of the protocol. All participants provided written informed consent to participate in the study. The study was approved by DRDC (# 2013-075) and University of Toronto (# 29914) Research Ethics Boards.
6.4.2 Demographic and Anthropometric Assessments:
Participants completed a questionnaire on demographics, which included information on marital status, education and ethnicity. Anthropometric measurements included height, weight, and body fat percentage. Body weight and height were measured without shoes, with light clothing, using standard, calibrated equipment (height and weight scales). Body composition (including percent body fat) was assessed using air-displacement plethysmography (BOD POD TM ). Body mass index was calculated as the body weight (kg) divided by the height (m) squared.
6.4.3 Dietary Intake Assessment
Dietary intake was assessed under two conditions: a) consumption of habitual at home food and beverage items for three days using a weighed food record (wFR) method and; b) ad libitum consumption of self-selected field rations of known macro- and micro-nutrient composition for eight days (2 consecutive days for each of four weeks) using either a wFR or a tablet app (full details below). Of the 18 ration menu item options (6 breakfast, 6 lunch and 6 dinner),
58 participants could self-select three standard military ration packs/day for two consecutive days each week for four weeks and were able to consume these rations ad libitum . On the third day, participants were instructed to bring back all unconsumed and/or partially consumed field ration packs.
All participants were trained in documenting, weighing and measuring their dietary intakes using either the wFR or the tablet and were provided with written instructions for reference during the recording period.
Food records (either reported using the wFR or the tablet app) were entered by two trained coders using a nutrient software program (ESHA © Food Processor SQL, version 10.13.1, 2013, ESHA Research, Salem, OR) and double-checked and analyzed by one trained study investigator. The weighed food record method has been previously used in populations of military personnel 29 . Study investigators reviewed food record details with the participant upon completion.
Assessment of intakes was derived from food and beverages only and participants were asked to refrain from the consumption of dietary supplements and performance enhancers. The nutrient values for the field rations were provided by CAF Directorate of Food Services. For nutrients that were missing (B-vitamins, potassium, magnesium, phosphorus, zinc,), values were taken from similar foods in the Canadian Nutrient File 2013 as part of the ESHA © (ESHA © Food Processor SQL, version 10.13.1, 2013, ESHA Research, Salem, OR) database.
6.4.4 Weighed Food Record (wFR)
Participants using the wFR method (3-days for habitual at home dietary intakes and 2-days (4 weeks; total 8 days) for field ration intakes) recorded the time, place (e.g. restaurant) and detailed description about each consumed food or beverage item. Food items were measured using measuring cups and/or a standard food scale (Cooking Stuff Kitchen Scale, Kitchen Stuff Plus, STK#65258) provided to the participants.
6.4.5 Tablet App
Participants using the tablet application, MyFitnessPal 127 , were provided with a Samsung Galaxy Tablet 3/Note 3 with the app pre-downloaded. The app, MyFitnessPal, was modified to
59 include a full list of CAF field rations and their nutritional composition. All items within the field rations are packaged with a pre-determined quantity and participants were able to search for their food/beverage item of choice and add it to the respective meal type option in the tablet app: breakfast, lunch and dinner and/or snacks.
6.4.6 Statistical Analyses
Descriptive statistics were used to present energy and nutrient data as means ± standard deviation (SD) or a percentage (%) of MDRI levels. Kolmogorov-Smirnov tests were used to examine the distribution of the data, and parametric and non-parametric analyses were used accordingly. Nutrient intakes were averaged across their respective days (3 days for home dietary intakes or 8 days for ad libitum consumption of field rations). Paired Student’s t-test or Wilcoxon matched-paired signed rank tests were used to compare intakes from self-selected field rations with home diets. Vitamin C, sodium, vitamin B3, vitamin B6, vitamin B12, folate, vitamin D, magnesium and zinc were found to be skewed, as a result, Wilcoxon matched-paired signed rank test was used to compare differences between home dietary intakes and field rations. For all other nutrients, paired Student’s t-test was used.
To assess the micronutrient intakes in CAF military personnel, both MDRIs and the Institute of Medicine’s (IOM) DRI recommendations were used for each individual in this sample of CAF personnel 80,82,98,99 . Energy was compared to the DRI recommendations for estimated energy requirements for males and females aged 19 and older with a moderate physical activity level. For all other nutrients, the MDRI and Estimated Average Requirement (EAR), or the AI when an MDRI and EAR was not available and the UL (for sodium) were used.
As this study consists of a convenience sample of 18 CAF military personnel, the sample was not treated as a group with a view to being representative of the entire CAF population. Therefore, we used the method identified in the IOM Applications in Dietary Assessment for nutrient assessment of individuals 82,128,129 . This method used the following variables in evaluating nutrient assessments for individuals: 1) the EAR requirement; 2) the observed intake (from 3-days of habitual diets and 8-days of field rations); 3) the day to day variability from the Continuing Survey of Food Intakes by Individuals 1994-1996 82 and 4) the 10% to 15% standard deviation of the EAR. This method was applied to the following nutrients assuming normal distribution and with coefficient of variation less than 60%: vitamin B1, vitamin B2, vitamin
60 B3, vitamin B6, calcium, phosphorus, magnesium, and potassium. It is important to note the caveats in using this method for assessing individual diets of this sample of CAF personnel; 1) the observed intake from home diets and from self selected field rations may not accurately reflect the individual’s true intake of the nutrient; 2) the estimates of within subject variation from data from the Continuing Survey of Food Intakes by Individuals 1994-1996 82 may not be reliable estimates of day-to-day variability in intake of military personnel (pertaining to variation in field rations and higher requirements); 3) this method was not applied to nutrients with a skewed distribution of daily intakes and with a coefficient of variation larger than 60 to 70% (vitamin A, vitamin C, Folate, vitamin B12, zinc and iron (for females), thus the proportion presented is a count of individuals below the EAR and as such, is not a reliable estimate of an individual’s usual intake; and 4) assessments of intakes with recommended MDRIs are presented as a proportion below MDRI. Therefore, the results presented with respect to the proportion of military personnel below DRI or MDRI should be interpreted with caution.
All data were analyzed using SPSS Statistics (version 24, 2012; IBM Corporation ®). A p-value of ≤0.05 was considered significant.
6.5 Results
6.5.1 Participant Demographics and Anthropometrics
Of the 18 CAF participants, 78% were male and 67% were Caucasians. The mean age was 34 ± 11 years, with a mean Body Mass Index (BMI) of 26 kg/m 2 and a mean percent body fat of 23%. The majority of the participants had a university degree (61%) (Table 1).
Table 1: Characteristics (demographics and anthropometrics) of the CAF study participants
Characteristics Study Participants (n=18) Age (years)1 34 ± 11 Sex 2 Male 14 (78%) Female 4 (22%) Height (cm) 1 174 ± 10 Weight (kg) 1 79 ± 13 Body Mass Index (kg/m 2)1 26 ± 4 (range: 21-32) Male 26 ± 3 (range: 21-31) Female 27 ± 5 (range: 21-32) Percent Body Fat (%) 23 ± 8 (range: 10-42) Male 20 ± 6 (range: 10-30)
61 Female 33 ± 8 (range: 22-42) Ethnicity 2 Caucasian 12 (67%) Asian 3 (17%) African American, Hispanic and South Asian 3 (17%) Education 2 High-school graduation 1 (6%) Non-university certificate 6 (33%) University Degree 11 (61%) Marital Status 2 Single 12 (67%) Married 5 (28%) Separated 1 (6%) 1Mean ± standard deviation (SD); 2n (%)
6.5.2 Dietary Intakes from Ad Libitum Consumption of Field Rations
Energy and Macronutrient Intakes:
Table 2 shows the amount of energy, carbohydrates, total fat and protein consumed per day based on averages of these nutrients in a sample of 18 menu combinations (6 menu varieties/meal type (6 breakfast, 6 lunch and 6 supper)) self selected by participants, if the full ration pack contents were consumed in their entirety. However, in this study, participants consumed, on average, 70% of their selected rations/day. From these rations, participants’ energy intake was 2688 ± 619 kcal/day with 60% of total energy from carbohydrates, 26% from fat and 14% from protein, all within the AMDR (Figure 1).
Table 2: Average amount of energy and macronutrients in self-selected field ration packs
IMP Energy (kcal) Carbohydrates (g) Total Fat (g) Protein (g) Breakfast 1344 221 41 31 Lunch 1432 224 41 43 Dinner 1317 200 39 42 Total/day † 4093 645 (63%) 121 (26%) 116 (11%) AMDR 45-65% 20-35% 10-35% The information in Table 2 is calculated from a sample of 2013 field ration menu items, as provided by CAF Directorate of Food Services. †The total/day corresponds to the total amount of nutrient available for consumption if the three ration packs (breakfast, lunch and dinner) were consumed in their entirety; AMDR = Average Macronutrient Distribution Ranges
62
At Home Actual Ration Consumption: Macronturient intakes as a percentage of total energy
14%
Carbohydrates Fat 26% 60% Protein
Figure 1: Macronutrient intakes of CAF personnel (n=18) as a percentage (%) of total energy from self-selected field rations (consumed at home for 8 days). The data were averaged for 8 days, collected using a tablet app or a weighed food record. The data was calculated using the energy contribution of 4kcal/g for carbohydrate, protein and 9kcal/g for fat.
Micronutrient Intakes:
A greater proportion of participants (range 5%-100%) consuming self-selected field rations had intakes less than the MDRI in comparison with the proportion of participants (range 0%-100%) below the DRI (EAR) for all other micronutrients (Table 3). The mean observed intakes of vitamin C, vitamin B2 and iron were acceptable in comparison to the recommended intakes (MDRI) (Table 4). However, the mean observed intakes of all other nutrients were less than the recommended intakes (MDRI) (Table 4). Based on the sodium upper limit of 2300 mg/day, all participants were consuming excess sodium from field rations (Table 4).
6.5.3 Habitual Dietary Intakes from Home Diets
Energy and Macronutrient Intakes:
Participants’ energy intake from home diets (using a weighed food record) was 2657 ± 580 kcal/day with 45% total energy from carbohydrates, 34% from fat and 19% from protein, which were found to be within the AMDR (Figure 1). The mean intakes of carbohydrates, fat and protein were 298 ± 85, 100 ± 28 and 127 ± 39 g/d, respectively (Table 4).
63
Usual Intakes from Home Diets: Macronutrient intakes as a percentage of total energy 2% 19%
Carbohydrates 45% Fat Protein Alcohol
34%
Figure 1: Macronutrient intakes of CAF personnel (n=18) as a percentage (%) of total energy from habitual dietary intakes at home (3 days). The data were averaged for 3 days, collected using a weighed food record. The data was calculated using the energy contribution of 4kcal/g for carbohydrate, protein and 9kcal/g for fat.
Micronutrient Intakes:
Greater than 50% of the participants had less than recommended intakes (MDRI) of vitamin A, vitamin D, calcium, folate and potassium in comparison to a lesser proportion below the DRI recommendations (Table 3). The mean observed intakes of most vitamins and minerals from home diets, in this sample of CAF personnel, were acceptable when compared to the DRI or MDRI levels, as shown in Table 4. Based on the DRI upper limit of 2300 mg/day, 83% of participants were consuming excess sodium (Table 3 and 4).
Table 3: Micronutrient intakes as a proportion of participants below DRI (EAR) and MDRI
Micronutrients Home a Rations b % below % below % below % below EAR MDRI EAR MDRI Vitamin A (μg) (RE) 50% 67% 100% 100% Calcium (mg) 56% 72% 89% 100% Iron (mg) 0% 17% 0% 17% Vitamin C (mg) 28% 39% 0% 5% Vitamin B1 (mg) 22% 22% 83% 100% Vitamin B2 (mg) 17% 17% 33% 39% Vitamin B3 (mg) NE 5% 17% 39% 77%
64
Vitamin B6 (mg) 11% 17% 83% 83% Vitamin B12 (μg) 22% 22% 66% 83% Folate (μg) (DFE) 50% 61% 95% 100% Vitamin D (IU) 88% 94% 100% 100% Magnesium (mg) 55% 72% 77% 100% Phosphorus (mg) 11% 11% 66% 95% Potassium (mg)† 83% 94% 100% 100% Zinc (mg) 28% 33% 66% 88% Dietary intake data collected for 18 CAF military personnel. aData are based on consumption of habitual at home food and beverage items for three days using a weighed food record or b70% consumption of self-selected field rations of known macro- and micro-nutrient composition for eight days using either a weighed food record or a tablet application. bField rations were a sample of 18 menu items (6 Breakfast, 6 Lunch and 6 Supper from 2013 The proportion of participants below the Estimated Average Requirement (EAR) was calculated using the Institute of Medicine’s assessment of nutrient intake for individuals. The within-person standard deviation was obtained using the Continuing Survey of Food Intakes by Individuals 1994-1996 from IOM’s Applications in Dietary Assessments Appendix B, page 191 82 . †The method for assessing intakes for nutrients with Adequate Intake (i.e. potassium) was used for nutrients without an EAR. Nutrients vitamin A, vitamin B12, vitamin C, iron (for females), folate have a skewed distribution of daily intakes, thus the proportion presented is a count of individuals below the EAR and as such, is not a reliable estimate of an individual’s usual intake. Assessments of individual intakes for military personnel compared with recommended Military Dietary Reference Intakes (MDRI) 98,99 is presented as a proportion below MDRIs. RE = Retinol Equivalents; NE = Niacin Equivalents; DFE = Dietary Folate Equivalents; IU=International Units.
6.5.4 Comparison of Intakes from Habitual Diets with Field Rations
There were no significant differences in total energy and saturated fat intake, but participants’ had significantly higher intakes of protein and fat, and lower intake of carbohydrates (p≤0.05) on their habitual at home diets in comparison to intakes from rations (Table 4).
The intakes of most vitamins and minerals were significantly higher from home dietary intakes in comparison to intakes from field rations, including vitamin A, calcium, B-vitamins (except B- 2), vitamin D, magnesium, phosphorus, potassium and zinc (p≤0.05). Although, there were no differences in vitamin B2, iron and sodium intakes, vitamin C intake was significantly higher from field ration intake in comparison with home dietary intakes (p≤0.05). Caffeine intake was significantly higher from home diets compared to that from field rations (Table 4).
Table 4: Comparisons between habitual at home dietary intakes and intakes from ad libitum consumption of self-selected field rations at home.
Nutrients (per day) MDRI/DRI † Recommendations Upper mean ± standard deviation (SD) (% of energy p-value Limit or % of MDRI) g Males (31-50y) Females (31-50y) Home Dietary Intake a Field Ration Intake b Energy (kcal)* c 3265 2228 N/D 2657 ± 580 2688 ± 619 0.80 Carbohydrates (g)* 130 130 N/D 298 ± 85 (45) 404 ± 93 (60) <0.001 Protein (g)* 56 46 N/D 127 ± 39 (19) 94 ± 19 (26) 0.002 Total Fat (g)* N/D N/D N/D 100 ± 28 (34) 77 ± 25 (14) 0.005 Saturated Fat (g)d Low Low Low 30 ± 9 (10) 28 ± 9 (9) 0.59 Total Sugar (g)e N/D N/D N/D 91 ± 46 (14) 172 ± 51 (26) <0.001 Fibre (g)* 34 38 28 25 N/D 25 ± 9 (74) 26 ± 8 (76) 0.52 Vitamin A (μg) (RE)** f 900 625 700 500 3000 g 936 ± 1181 (108) 310 ± 117 (37) 0.04 Calcium (mg)* 1000 800 1000 800 2500 862 ± 348 (86) 563 ± 184 (56) 0.003 Iron (mg)* 8 6 18 8.1 45 20 ± 8 (219) 20 ± 5 (222) 0.76 Vitamin C (mg)** 90 75 75 60 2000 139 ± 109 (159) 248 ± 117 (284) 0.003 Sodium (mg)** <2300 1500 <2300 1500 2300 3962 ± 1597 (264) 4191 ± 884 (279) 0.65 Vitamin B1 (mg)* 1.2 1.0 1.1 0.9 N/D 1.6 ± 0.7 (138) 0.6 ± 0.2 (50) <0.001 Vitamin B2 (mg)* 1.3 1.1 1.1 0.9 N/D 2 ± 0.8 (160) 2.6 ± 2 (208) 0.28 Vitamin B3 (mg) (NE)** 16 12 14 11 35 30 ± 19 (191) 12 ± 4 (75) <0.001 Vitamin B6 (mg)** 1.3 1.1 1.3 1.1 100 3 ± 4 (220) 0.7 ± 0.2 (54) 0.03 Vitamin B12 (μg)** 2.4 2.0 2.4 2.0 N/D 19 ± 33 (805) 1.5 ± 0.7 (62) 0.03 Folate (μg) (DFE)** 400 320 400 320 1000 394 ± 271 (99) 170 ± 79 (42) 0.003 Vitamin D (IU)** 600 10 600 10 4000 195 ± 168 (33) 37 ± 38 (6) <0.001 Magnesium (mg)** 420 350 320 265 350 366 ± 216 (92) 165 ± 46 (42) <0.001 Phosphorus (mg)* 700 580 700 580 4000 1195 ± 366 (171) 462 ± 108 (66) <0.001 Potassium (mg)* 4700 4700 N/D 2879 ± 1288 (61) 785 ± 244 (17) <0.001 Zinc (mg)** 11 9.4 8 6.8 40 14 ± 8 (131) 6 ± 2 (63) <0.001 Caffeine (mg)* N/D N/D N/D 139 ± 107 48 ± 39 <0.001 Dietary intake data collected for 18 CAF military personnel. aData are based on consumption of habitual at home food and beverage items for three days using a weighed food record or b70% consumption of self-selected field rations of known macro- and micro-nutrient composition for eight days using either a weighed food record or a tablet application. Field rations were a sample of 18 menu items (6 Breakfast, 6 Lunch and 6 Supper from 2013). Nutrient values were provided by CAF Directorate of Food Services, except for B-vitamins, potassium, magnesium, phosphorus and zinc, which were obtained from similar foods in the Canadian Nutrient File 2013 as part of the ESHA © Food Processor software.
65 66 †Recommendations are Military Dietary Reference Intakes (MDRIs) and DRI (Estimated Average Requirement (EAR)) or Adequate Intake (AI) 98,99 , except for energy and macronutrients (from the Institute of Medicine’s Energy and Macronutrient Recommendations). c Energy recommendations based on estimated energy requirements of highly active Canadian individuals using the formula 80 : males: EER=662 - 9.53 X age+1.48 X 15.91 X weight + 539.6 X height; females: EER=354-6.91 X age+1.45 X 9.36 X weight + 726 X height; Macronutrients as a percentage (%) of energy are as follows; carbohydrates (45% - 65%), fat (10% - 35%) and protein (20% - 35%). d Saturated Fat recommendation is “as low as possible while consuming a nutritionally adequate diet” 80 ; eNo recommendations for Total Sugars but Added Sugars are limited to “no more than 25% of total energy” 80 . fThe UL applies to retinol only. gFibre and micronutrient intakes expressed as a percentage (%) of MDRI. *Paired Student’s T-test or **Wilcoxon-Matched Paired Signed Test was used to compare differences in nutrient intakes between home diets and field rations. p-value is the significance level for differences between home dietary intake and field ration intake. N/D = not determined; RE = Retinol Equivalents; NE = Niacin Equivalents; DFE = Dietary Folate Equivalents; IU = International Units.
6.6 Discussion
The primary objective of this study was to compare ad libitum intake from field rations under thermo-neutral comfortable conditions with home diets. The results of this study do not support the hypothesis that reduced energy intake when consuming field rations is due to the palatability of the field rations (in an acute setting), as there was no difference in energy intake between consumption of field rations and home diets. Although, the study was not designed to assess adequacy of nutrient intakes, participants in this study had less than the recommended intakes of vitamin A, vitamin D, folate, calcium, magnesium and potassium from their home diets, with additional lower intakes of B-vitamins, zinc and phosphorus from self-selected field rations.
Using the methods of wFR and tablet app, we were able to accurately quantify intakes from field rations as we had measurements of both total intake and food waste. We did not measure food waste from habitual dietary intakes and data are from self-reported dietary methods only. Our previous research has demonstrated that there was a low rate of underreporting and that there were no differences between participants using the tablet app or the weighed food record method to record their consumption of field rations 130 (Chapter 9).
Contrary to the healthy Canadian adult population, where the majority of individuals are exceeding their energy requirements 131 , the participants in this study had acceptable energy intake from habitual diets (2657 kcal/d) and field rations (2688 kcal/d) for average physical activity levels but not for very active individuals. Previous studies have indicated comparable energy intakes (range: 1069 – 3231kcal/d) under non-operational settings 22,29,132,133 in non- Canadian military personnel.
Although their carbohydrate (45%) and fat (34%) intakes from habitual diets were comparable to those of the healthy Canadian adult population (50% and 31%, respectively) 134 , the participants in this study had relatively higher intakes of carbohydrates (60%) and lower intakes of fat (26%) from field rations in comparison to habitual dietary intakes. Carbohydrates are considered the primary source of energy and within a CAF population, it is critical that they obtain a significant percentage of their total energy from carbohydrates during demanding activities 12 . Research has shown that depletion in carbohydrate stores are more likely associated with negative energy balance in comparison with either protein or fat 18,101 . Therefore,
67 68 maintaining adequate carbohydrate intakes (and thereby maintaining glycogen availability) significantly impacts physical performance 18 . Hence, the current amounts of carbohydrates found in field rations are beneficial to CAF personnel when on operational duties. However, CAF personnel are consuming a high amount of carbohydrates as total sugar both from their habitual diets (91g) and from field rations (172g), the latter which is higher than that of the Canadian population (115g) 131,135 . Longer-term excess consumption of these simple carbohydrates may have health implications 136 . A balanced diet high in complex carbohydrates (these items also contain relatively higher levels of vitamins and minerals) will enhance the nutrient profile of military personnel and benefit them in sustaining energy for both short and long-term missions 137 .
Anecdotal reports indicated a preference for high protein intakes within our group of CAF personnel, which was also demonstrated in their habitual at home diets. This is also similar to the higher protein intakes seen in other physically active individuals such as athletes 138,139 . Protein shakes were the main source of protein in the home diets of our participants. Based on the predicted level of protein intake for military personnel (1.61g/kg/day) 5, CAF personnel may not be acquiring appropriate amounts of protein from their selected combinations of IMPs alone. It is likely that CAF military members are acquiring additional protein in operational scenarios through personal supplementation or provision of additional foods 70 . Available scientific data supports high-protein intakes for short-term operations for military personnel 140 , but current recommendations for military personnel do not suggest increasing protein requirements until further research on the utilization of protein in relation to operating in environmental extremes is considered 3.
Participants in this study were not meeting the recommendations for fibre both from home diets and from field rations, which is comparable to data from the healthy Canadian adult population 134 . Although no studies thus far have looked at the impact of field rations on bowel habits of CAF soldiers, studies from other nations have demonstrated diarrhea and constipation (as a result of longer-term exclusive consumption of ration packs) to interfere with daily combat performance 141 . Additionally, anecdotal reports from our troops inform us of related bowel problems with long-term use of field rations. These ration packs contain less than recommended amounts of fibre (31 grams), which may play a role in adversely affecting soldier’s bowel habits. However, higher than recommended amounts of fibre could interfere with tactical
69 mobility in situations with limited water availability and where frequent bowel movements are undesirable 9. As such, further research is required to better understand the combined effect of both field rations and operating conditions on bowel habits.
In this study, a proportion of participants did not meet the EAR or MDRI goals for some micronutrients from their habitual home diets. The findings of intakes lower than the recommended intakes of vitamin A, vitamin D, calcium, magnesium, potassium and folate from their home diets are comparable to the low micronutrient intakes of healthy Canadian adult populations, where the prevalence of inadequacy for vitamin A, vitamin D, calcium and magnesium ranged from 40% to 87% 131 . Although, the low intakes of potassium cannot be conclusively determined due to the limitations of the AI for nutrient assessments 131,142 , it can be inferred that intakes lower than the AI are likely also below the recommended intake. This may, in part, be explained by the low intakes of fresh fruits and vegetables and a higher consumption of processed and refined foods in this sample of CAF personnel. In contrast, participants had a higher intake of B-vitamins in home diets, which can be attributed to the specific composition of the protein shakes that our participants indicated consuming. Similarly, iron intakes from home diets were found to be acceptable in comparison with MDRI levels, although we cannot infer adequacy due to the skewed distribution of iron in menstruating women. These findings are similar to those for the Canadian adult male population, however, 16-19% of Canadian women aged 19 years and older have lower intakes of iron 131 .
Military personnel experience high-intensity physical activity in temperature extremes and in some cases, excessive losses of micronutrients may occur because of sweating. Additionally, operating or training in temperature extremes may also result in higher requirements of certain micronutrients. As such, increased amounts of certain micronutrients may be recommended. In this study, even though participants self-selected their field rations, they did not consume the rations in their entirety. Field rations generally provided less than desirable content of some vitamins and minerals (e.g. potassium, vitamin D) due to the difficulty of providing fresh fruits, vegetables and dairy products in ration packs 70 . As a result, most of them had lower than recommended intakes (MDRI) for these vitamins and minerals. Studies in non-Canadian military personnel have also demonstrated less than recommended intakes of micronutrients (e.g. vitamin D, calcium and magnesium) from rations 22,29,47,143 . Considering the strenuous physical and mental demands on military personnel on operational duties and the increased risk
70 for bone-related injuries 22,47 , research has also indicated the need to further consider the vitamin D status of military personnel operating or training at high latitudes. In contrast, Vitamin C intake was found to be high from field rations. In the absence of fresh fruits and vegetables in the combat rations, participants were consuming most of this nutrient through the vitamin C- fortified drink crystals (as part of the field ration packs). Similarly, iron intake was found to be acceptable compared with the MDRIs. However, this study was not able to address the differences in intakes between sexes due to the small number of female participants, however, previous research has indicated iron deficiency in female military personnel 144-146 . Thus, further research assessing iron intakes in a larger population of CAF military personnel, particularly females, during long-term operational duties should be considered 146 .
Considering the functional roles of micronutrients in maintaining overall health, less then recommended intakes of some vitamins and minerals could potentially contribute to increased risk of injuries and decreases in cognitive and physical performance, if intakes were to extend for periods longer than those investigated. However, our results may not be representative of all CAF personnel, as the sampling was not designed to be representative of the CAF and, the small sample size. Additionally, home dietary intakes as observed in this study may vary depending on operational levels and varying physical activity and fitness regimens of military personnel. However, when habitual nutrient intakes are less then optimal, the nutritional status of a soldier during situations of low-nutrient intake (e.g. deployment) is likely to be impacted 7. As such, strategies to encourage optimal habitual dietary intakes of soldiers will play a role in enhancing subsequent physical and cognitive performance. Meeting the recommended intakes of these nutrients in the home diets of CAF could be emphasized by educating CAF personnel in preparing more home-cooked meals and for example, consuming less fried foods and sugar sweetened beverages.
Depending on the selected ration menu combinations and the amount consumed, participants consuming field rations may or may not meet the MDRI recommendations for micronutrients. Importantly, the rations were not consumed in their entirety, even at home, when CAF personnel were not constrained by operational demands, contributing to less than recommended intakes, which could be exacerbated if rations were to be consumed for longer periods of time under arduous conditions. Also, considering the increased demands of physical training and operations, the requirements for micronutrients are likely higher for CAF military personnel in
71 comparison to those recommended for the Canadian adult population 70 . As fresh fruits/ vegetables, legumes and dairy products are a major source for many of these nutrients (including vitamin A, vitamin D, potassium, and B-vitamins), further investigation into strategies to include more sources of these food groups within combat rations is warranted. Assessments of adequacy of intakes in this study, however, should be interpreted with caution because they are based on individual assessments of nutrient intakes with statistical approaches and variance estimates that may not be reliable estimates of intakes from field rations or of habitual intakes of military personnel. The results demonstrate potentially less than recommended intakes (compared to MDRIs) of some micronutrients but do not indicate inadequacies of any micronutrients in the participants.
Sodium intakes from habitual at home diets and from field rations were in excess of both the AI and the UL, which is similar to intakes seen in the Canadian adult population 131,147 . Sodium is an important component in food preservation and plays a significant role in keeping field rations stabilized during long-term storage under non-refrigerated conditions 9. In addition, the sodium requirements are set for a sedentary healthy Canadian adult population and not for situations of increasing sweat loss as a result of heavy workloads in hot environmental temperatures where additional sodium may be required 9,148 . Recommendations for sodium intake for military personnel are approximately 5000 mg/day for male members, whereas recommendations for sodium content in operational rations can be up to 7000 mg/day as a result of military members being able to sustain sodium losses through sweat with varying levels of physical output while operating in the hot environment 70 . However, a number of studies have demonstrated a link between excess sodium intakes and hypertension, thus contributing to an increasing risk of cardiovascular and renal diseases 148 . CAF personnel are possibly able to tolerate excess sodium intakes while operating in strenuous conditions in hot environments, but research remains equivocal with regards to appropriate sodium levels upon acclimatization when operating or training in temperature extremes (e.g. hot and cold). Additionally, whether such high habitual sodium intakes may lead to increasing risk of chronic diseases for highly active military personnel is still unknown.
Although there are no recommendations for caffeine, Health Canada indicates consumption of caffeine below 400mg/d is not associated with adverse effects 149,150 . Contrary to the high caffeine intake of Canadian adults 151 , CAF participants had moderate intakes of caffeine.
72 Caffeine is found in many performance enhancers and energy drinks and because participants were asked to refrain from consumption of such supplements during this study, it is likely that we are underestimating habitual intakes of caffeine in this population.
This study is the first to investigate, under nonoperational conditions the ad libitum intakes from self-selected field rations in comparison to home diets in a convenience sample of CAF personnel and to compare both with DRI and MDRI recommendations. This study is strengthened by the use of valid and reliable dietary assessment tools to assess diet as well as the high compliance of the study participants and minimal misreporting bias 130 . In addition, this study benefited from one-on-one training for each participant to ensure accurate recording of dietary intake, which may not be feasible for larger studies. Since military personnel are required to maintain optimal performance and health, the results from this study can better inform evidence-based practices to ensure optimal preparation of military personnel prior to deployment, with respect to appropriate nutrition and therefore, is potentially of interest to healthcare practitioners and military commanders.
6.7 Conclusions
In this study, we showed that CAF participants consumed similar amounts of energy from ad libitum consumption of self-selected field rations as they did at home, thus the palatability of the rations is likely not an important factor in the under-consumption of energy (i.e. voluntary anorexia seen in military personnel) in an acute setting. While recognizing the methodological limitations of this study with regard to assessing the nutrient intakes of individual CAF personnel, the data demonstrated that they had less than recommended intakes (in comparison with MDRIs) of some micronutrients from their home diets as well as from self-selected consumption of field rations. Like many Canadians, they may not follow a nutrient-dense diet at home that is optimal for ensuring operational readiness. These results may warrant further investigation into optimal ways to ensure sufficient macronutrient and micronutrient intakes, particularly when field rations are consumed for extended periods of time.
6.8 Acknowledgements
The authors would like to acknowledge the assistance of DRDC staff involved in recruiting participants and data collection and representatives of the Surgeon General of the Canadian
73 Armed Forces co-hosted within the DRDC research centre, the Canadian Forces Environmental Medicine Establishment (CFEME), for provision of experimental medical support. The authors thank the CAF personnel of DRDC, CFEME and Dennison Armouries, Toronto, Ontario for volunteering to participate in this study. The authors acknowledge Charles Ko and Stephanie Li for help with data input of the food records.
6.9 Funding/Support Disclosure
Ira Jacobs was the principal investigator responsible for the research contract-funding proposal and to whom the funding was awarded that supported this research. This study was funded by a Defence Research and Development Canada research contract awarded to University of Toronto. Mavra Ahmed was also supported by a Canadian Institute of Health Research (CIHR) Strategic Collaboration in Public Health Policy Fellowship and an Ontario Graduate Scholarship during her candidature.
6.10 Conflict of Interest
No potential conflict of interest was reported by the authors.
6.11 Addressing Links to Next Chapter
This study investigated the habitual dietary intakes of CAF personnel, which have not been assessed previously. Additionally, we also characterized intake from ad libitum intake of field rations under thermo-neutral at home conditions. We showed that participants consumed similar amounts of energy, be it from their home diets or field rations under these conditions and as such, the palatability of the rations is likely not an important factor in the under- consumption of energy (i.e. voluntary anorexia seen in military personnel). However, conducting demanding physical activities in extreme environmental temperatures play a major role in determining energy intakes. As such, the next study will assess how energy intake is impacted by differing environmental temperatures and with and without demanding physical activity.
74
Chapter 7
Comparisons of Dietary Intakes of Canadian Armed Forces personnel consuming field rations under acute hot, cold and temperate conditions with simulated strenuous physical activity
This study is under review with co-authors.
This study addressed objective #3 & 6 of my thesis; a) To measure energy and nutrient intakes when consuming field rations in an experimental laboratory setting under controlled temperature (e.g. temperate, hot and cold) and humidity chamber in combination with precisely measured physically demanding activities; b) To measure subsequent energy and nutrient intakes post- experimental treatments; and c) To examine the levels of nutrient-related biomarkers in relation to ration consumption and ambient temperature extremes in an acute setting.
Student’s contribution:
I was involved in developing the experimental protocol for this study in collaboration with Iva Mandic, Dr. Len Goodman, Dr. Ira Jacobs and my supervisor, Dr. Mary L’Abbé . I conducted the study (in collaboration with Iva Mandic), collected, entered and analyzed the data (dietary intakes). I independently learned the data analysis and reviewed it with Dr. Wendy Lou to ensure my statistical analyses and interpretations of the data were accurate. I independently prepared a draft of the manuscript prior to engaging my co-authors in reviewing and revising the manuscript for subsequent publication.
75 Comparison of dietary intakes of Canadian Armed Forces personnel consuming field rations under acute hot, cold, and temperate conditions with simulated strenuous physical activity Mavra Ahmed 1, Iva Mandic 2, Wendy Lou 3, Len Goodman 4, Ira Jacobs 2 and Mary R. L’Abbé 1,*
1 Department of Nutritional Sciences, University of Toronto, Toronto, M5S 3E2, Canada; [email protected] (M.A.); [email protected] (M.L.) 2 Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, M5S 2W6, Canada; [email protected] (I.M.); [email protected] (I.J.) 3 Dalla Lana School of Public Health, University of Toronto, Toronto, M5T 3M2, Canada; [email protected] 4 Defence Research and Development Canada – Toronto Research Centre, Toronto, M3K 2C9, Canada; [email protected]
* Correspondence: [email protected]; Tel.: +1-416-978-7235
Keywords: nutrient intakes, military personnel, physical activity, temperature extremes
7.1 Abstract
Background and Objective: Military personnel frequently encounter metabolically challenging training or deployment conditions and are known to not eat enough during these military operations. Dietary Reference Intakes, designed for the healthy Canadian adult population, are used to guide the energy content of the Canadian Armed Forces field rations provided to personnel deployed to the field for training or operations. However, the high-energy expenditures likely to occur under such conditions may not be adequately considered. The primary objective of this study was to examine energy and nutrient intakes of CAF personnel consuming field rations in a resting thermo-neutral environment and under simulations of standardized strenuous military activities and with varying environmental temperatures.
Methods: Dietary intake from ad libitum field ration consumption by a convenience sample of 18 CAF participants (mean age 33 y) was assessed using measured food intake/food waste method using a randomized crossover design under four different experimental treatments: 1) sedentary treatment (21°C) (control), and during 8h of a range of operational–like physical activities (light to strenuous) in a temperature chamber controlled at; 2) hot (+30°C), 3) cold (-
76 10°C), and 4) temperate (21°C) treatments. Dietary intakes were also measured for the rest of the day post-experimental treatments. Linear Mixed Models using Bonferroni adjustment was used to determine the differences in intakes.
Results: Participants consumed 70% (1970 ± 718 kcal/8hours) of the total energy (2776 kcal) available in the field rations during the experimental treatments. Average percentage energy intake from carbohydrates, fat and protein were, 59%, 28%, 13%, respectively. Energy and macronutrient intake did not differ among temperature or activity levels; however, specific micronutrients (vitamin C, calcium and magnesium) were significantly different ( p≤0.05). There were significant differences between experimental treatments in water intake (sedentary Conclusions: Participants’ energy intake from field rations under hot, cold and temperate treatments were similar to the energy intake during the sedentary treatment, even with an acute challenge of increased energy expenditure and temperature stress in the simulated field conditions. This may have implications for insufficient energy intake in relation to the energy requirements of CAF personnel performing strenuous physical activities under prolonged exposure to climatic extremes. 7.2 Introduction Military personnel frequently encounter metabolically demanding operations under conditions of environmental extremes (e.g. desert, arctic) 12,19 . The physical demands encountered by military personnel can range from sedentary to energy demands as high as 10,000 kilocalories (kcal) per day in some cases 12,23 . Moreover, activities with minimal energy requirements may become quite demanding under environmental stress 2,12 . The success of operations may in part be determined by the degree of acclimatization to these extreme environmental conditions, and where the body’s metabolic response to the temperature extremes is increasingly dependent upon adequate nutrition 15,20 . Military field rations are the principal source of nutrients provided to Canadian Armed Forces (CAF) personnel for operations in all environments 19 . Dietary Reference Intakes (DRIs) designed for the healthy Canadian adult population 80 , are used to guide the energy and nutrient 77 content of CAF field rations 11 . These rations are intended to be nutritionally sufficient for standard military operations but may not adequately consider some of the strenuous and demanding operations that military personnel encounter during training and/or combat operations 11 . On top of these standard food allowances, additional food (or incremental allowances) may be provided in conditions where greater sustenance is warranted (e.g. under climactic extremes) 10,11 . Incremental Allowances (IA) are expressed as a cost over and above the standard food allowances that are required to feed military personnel under such arduous conditions and may be provided where standard allowances may be insufficient to fuel the energy demands of metabolically challenging operations under climatic extremes 10,11 . Although high-energy expenditures are expected during field operations, particularly those involving ambient temperatures extremes, these IA are not based on empirical evidence of the increased energy demands under such conditions 11 . Moreover, such arduous conditions frequently lead to a gap between the amounts of food provided versus the amount that is actually consumed 5,15 . This challenge is further compounded by additional factors such as palatability/variety of rations provided, cooking method, time to eat and load carriage 5,9,11,152 . As repeatedly demonstrated in the literature, these factors play a role in contributing to voluntary anorexia, which is defined as failure to consume foods that are offered or readily available under situations of extreme stress 4,5,30,100 . This voluntary anorexia can have negative psychological and physiological consequences, thereby impacting operational readiness and performance 5,15,16,18 . It is likely that military personnel may compensate for voluntary anorexia by increasing their energy intake when time permits or when situations of stress have been overcome. However, strenuous physical activity and environmental temperature at which the exercise is performed may also influence the energy intake in the post-operating meals 44,153 . The extent to which CAF military personnel may compensate for this voluntary anorexia demonstrated during operations in harsh environmental conditions by subsequently consuming additional energy once the operational duties have subsided and/or they have time to eat is unknown. Nutritional biomarkers act as indices of biological or physiological responses to dietary behaviour (in this case, consuming field rations) 93,94 , and can help assess the impact of acute or prolonged consumption of field rations on nutrient status. Additionally, nutritional biomarkers can also help address requirements for nutrients under conditions of environmental stress and strenuous physical activities. For example, research has indicated potential sweat losses of 78 minerals and vitamins that may warrant an increase in dietary intake of these nutrients 61,67,125,154 but there is very limited research in this area, especially for military personnel operating in environmental extremes 70 . Although much of the scientific research on environmental nutrition and physiology was the focus of investigations after WWII 12 , there is paucity of research in the recent literature regarding the quantification of energy intake in relation to potential energy deficits as a result of strenuous physical activities in harsh environmental temperatures in Canadian military personnel. The majority of the studies conducted with Canadian military personnel did not accurately assess energy and nutrient intakes along with accurate measures of energy expenditure 9,17,18 . For example, only one study used a direct method of assessing energy expenditure (doubly-labelled water), however, the use of self-reported food records limit the accurate assessments of dietary intake in this study 17 . In addition, many were not designed to assess the dietary adequacy of specific micronutrients (e.g. sodium, B-vitamins) that may have altered requirements in conditions of environmental stress and did not investigate the requirement for an increase in energy content of rations under these conditions 9,12,17,18 . Furthermore, majority of these studies are dated and since then, there have been changes in the demographics of CAF personnel, advances in CAF tactics/technologies or operational duties and changes in nutritional intakes and modified perceptions of ‘healthy’ foods 155 . Additionally, data is limited on investigating the impact of subsistence on rations and performance of physically demanding activities under environmental stress on concentrations of biomarkers in CAF personnel. Using the measured food intake/waste collection method (current gold standard in dietary assessment methodology), the primary objectives of this study were to: 1) measure energy and nutrient intakes of CAF personnel consuming field rations ad libitum in an experimental laboratory setting in a temperature and humidity controlled chamber (e.g. temperate, hot and cold) in combination with precisely measured physically demanding activities and; 2) measure energy and nutrient intakes from subsequent ad libitum ration consumption after the completion of strenuous physical activities in harsh environmental temperatures. The secondary objective of this study was to examine the levels of nutrient-related biomarkers in relation to ration consumption and ambient temperature extremes. 79 7.3 Methods 7.3.1 Study Participants The experimental trial consisted of a convenience sample of 18 CAF personnel who were Regular Force or Class A Reservists (sample was not selected to be representative of the entire CAF population). A detailed description of the study can be found in the technical report prepared by University of Toronto for Defence Research and Development Canada (DRDC) 126 . A total of 27 participants initially volunteered for the study. Two participants never started the protocol and an additional 7 participants dropped out due to scheduling difficulties and/or non- compliance due to the demanding nature of the protocol. All participants provided written informed consent to participate in the study. The experimental trial was approved by DRDC (# 2013-075) and University of Toronto (# 29914) Research Ethics Boards. Assuming that energy intake is similar to that found by Shorten et al., 44 , in order to see a 10% difference in energy intake between the four experimental treatments with a power of 80% and a 0.05 significance level, 12 participants were required. Even with a predicted 40% attrition rate (due to the demanding nature of the protocol), our recruited sample of 25 military personnel would be more than sufficient. 7.3.2 Experimental Design The study was a randomized crossover design where each participant attended the laboratory on six separate occasions. The initial two visits consisted of the consent process, completion of the Physical Activity Readiness Questionnaire-Plus (PAR-Q+), collection of demographics and anthropometric measurements, measurement of aerobic capacity and body composition; followed by four experimental trials conducted in an environmental chamber (temperature and humidity controlled) and administered in a randomized counterbalanced design: exercise in the heat (30 °C) (hot), exercise in the cold (-10 °C) (cold), exercise in a thermo-neutral temperature (21 °C) (temperate) and a resting condition (21 °C) (sedentary). 80 Figure 1: Environmentally-Controlled Chamber Laboratory Simulation Experimental Design Randomized crossover experimental design where treatments refer to hot, cold, temperate (with strenuous physical activities) and sedentary. Visit sessions 1-4 refer to the 8-hour long experimental treatment in temperature and humidity controlled environmental chamber. The following were collected and/or measured at study visit session A (informed consent), B (socio-demographic/anthropometric information, maximal oxygen consumption), C (body composition and urinary/blood biomarkers) and D, E, F, G (urinary and blood biomarkers and completion of questionnaires). 7.3.3 Demographic and Anthropometric Assessments Participants were asked to complete a questionnaire on demographics that included information on ethnicity and education level. Anthropometric measurements included height, weight, and body fat percentage. Body weight and height were measured without shoes, with light clothing and using standard, calibrated equipment (height and weight scales – HealthOMeter Continental Scale Corp., Bridgeview ILL, USA). Body composition (including percent body fat) was assessed using air-displacement plethysmography (BOD POD TM ). Body mass index (BMI) was calculated as the body weight (kg) divided by the height (m) squared. 7.3.4 Dietary Intake Assessment This manuscript provides an assessment of the energy and nutrient intakes consumed ad libitum within the experimental trial sessions (8-hour) and for the subsequent meals within the 24-hour period. Participants were able to consume three self-selected standard military ration packs per experimental trial ad libitum . Participants were also provided with a dinner ration pack and/or 81 light meal combat ration pack to consume ad libitum later that day under thermo-neutral conditions (e.g. at home). Participants were asked to refrain from the consumption of foods other than those found in the rations as well as dietary supplements and performance enhancers. The rations contain pre-packaged, pre-labelled food and beverage items (e.g. sliced apples, bread, coffee, breakfast sausages etc.). The foods and beverages within these rations are of precisely known quantity and nutrient composition. Although, participants could only consume the beverages (e.g. sports drink, coffee, tea, vanilla cappuccino) provided within the rations, they were able to have water ad libitum. Dietary intake was assessed using the measured food intake/waste method (considered the current gold standard in dietary assessments), under the four experimental treatments. Study coordinators (MA or IM) were in the chamber with the participant for all of their visits and documented the consumption of foods and/or beverages (including water). All unconsumed and/or partially consumed food and beverage items were weighed and recorded by study coordinators to the nearest g or ml, using a standard food scale (PrepTech, PT-800, Newport Beach, CA). The measured food intake/food waste was calculated from the amount unconsumed subtracted from the known quantity of each menu item selected. Food intake was entered by two trained coders using a nutrient software program (ESHA © Food Processor SQL, version 10.13.1, 2013, ESHA © Research, Salem, OR), which was pre-loaded with nutritional information for all the food and beverage components found within the field rations and double-checked and analyzed by the study investigator (MA). The nutrient values of food and beverages in the combat/field rations were provided by CAF Directorate of Food Services. For nutrients that were missing (B-vitamins, potassium, magnesium, phosphorus, zinc,), values were taken from similar foods in the Canadian Nutrient File 2013 as part of the ESHA © (ESHA © Food Processor SQL, version 10.13.1, 2013, ESHA Research, Salem, OR) database. 7.3.5 Urinary and Blood Biomarkers Participants were instructed to collect their urine for 24 hours (including 8 hours in chamber and at home post-treatment). Participants were provided with a plastic container to collect their urine and a leak-proof bag in which to store their urine container. Participants were instructed to 82 discard the first urine sample of the day and to collect all subsequent urine for the next 24 h, including the first urine sample on the following day. Venous blood samples (10 mL) were collected from each participant after an overnight fast. Erythrocytes and plasma were separated within 1 hour of collection. Both the urine and plasma samples were shipped to a third party blood chemistry laboratory (Lifelabs, Toronto, ON, Canada) for processing. Creatinine excretion was used to assess the adequacy of the urine collections, using creatinine excretion standards (<8.8 mmol/day for males and <4.5 mmol/day for females) 156 . 7.3.6 Experimental Trials Each participant completed the four experimental treatments individually with 1 week between visits. Participants were asked to refrain from alcohol consumption and vigorous physical activity in the 48 h preceding the experimental trials. Participants’ self-selected three standard military ration packs (of the 18 ration menu items (6 breakfast, 6 lunch and 6 dinner) available) per experimental trial. Although the ration menu items differed between participants, each participant consumed the exact same menu items for each of the 3 self-selected military ration packs for their 4 experimental visits. For each of the four experimental trials, participants arrived at the laboratory at 0700 in a fasted state. On arrival, participants were weighed and had their resting blood pressure measured using an automated blood pressure cuff (Omron Health Care, Kyoto Japan). An initial blood sample was taken and then participants were provided with the breakfast meal from their self-selected ration packs. Participants were instructed to wear temperature appropriate military clothing for the environmental treatments they were to complete. Participants were randomized to enter the environmental chamber maintained at either 30 °C (hot), 21 °C (sedentary and temperate), -10 °C (cold), with relative humidity of 30% for all treatments. Following entry into the chamber, participants either rested for 8 hours (sedentary) or performed two 2-hour (total 4 hours) circuits composed of typical military tasks (covering a range of light, moderate and heavy work loads (Table 1)), followed by a two 2-hour (total 4 hours) rest period, during which they could consume foods and beverages ad libitum from the self-selected ration packs. Study coordinators, based on participants’ request, prepared the 83 foods and beverages from the ration packs in advance of the 2-hour rest periods. The preparation of food items typically required heating the food item with a flameless food heating sleeve (Truetech Inc. Riverhead, NY) and/or addition of hot water (e.g. for items such as cereals, rice, couscous), which was done outside the environmental chamber. Study coordinators also prepared the sports drink and/or coffee-based beverages (preparation requires addition of hot or cold water) if participants requested these items while performing the physical activities or at rest. At the end of each experimental visit day, participants were provided with a dinner ration pack and/or light meal combat ration pack to consume later that day under thermo-neutral conditions (e.g. at home) and were instructed to refrain from any foods or beverages (except water) not found within the field rations. Participants could choose additional food in the form of a light meal combat ration pack (on top of the standard IMPs) if they wished (and they could consume these rations ad libitum ). On the next day, participants were instructed to bring back all unconsumed and/or partially consumed field rations. Table 1: Representative military-specific tasks simulated in the environmental chamber; sample experimental day (Source credit: Iva Mandic 126 ) Block Time Activity 1(ACTIVE) 8:00- Walking on a motorized treadmill – Walked at speed of 2.4km/h at the 8:09 following grades 0%, 5% and 10% with no load 8:09- Walking on a motorized treadmill – Walked at speed of 4km/h at the following 8:18 grades 0%, 5% and 10% with no load 8:18- Walking on a motorized treadmill – Walked at speed of 5.6km/h at the 8:27 following grades 0%, 5% and 10% with no load 8:30- Empty ammo can passing – Move empty ammo can from one 123.8 cm high 8:32 stand to another and back continuously 8:35- Full ammo can passing – Move full ammo can (13.7kg) from one 123.8 cm high 8:37 stand to another and back continuously 8:40- Moving sandbags – Moving two 20kg sandbags, carried them 7.4m, put them 8:42 down, walked back empty handed and picked up another 2 sandbags 8:45- Stoop/kneel – On both knees, on one knee or crouched on toes 8:50 8:50- Full jerry can carry – Move two 20kg jerry cans, carried them 7.4m, turned 8:52 around and carried them back, turned around and continue 8:54- Full jerry can carry – Move two 20kg jerry cans, carried them 7.4m, turned 8:56 around and carried them back, turned around and continue 9:00- Walking on a motorized treadmill – Walked at speed of 2.4km/h at the 9:09 following grades 0%, 5% and 10% with 10kg load (daypack) 9:09- Walking on a motorized treadmill – Walked at speed of 4km/h at the following 9:18 grades 0%, 5% and 10% with 10kg load (daypack) 9:18- Walking on a motorized treadmill – Walked at speed of 5.6km/h at the 84 9:27 following grades 0%, 5% and 10% with 10kg load (daypack) 9:30- Empty ammo can load (load and unload truck simulation) – Lift empty ammo 9:32 can (3.2kg) from one low stand (8.9cm) onto a high stand (174.6cm) and brings it down again continuously 9:35- Full ammo can load (load and unload truck simulation) – Lift full ammo can 9:37 (13.7kg) from one low stand (8.9cm) onto a high stand (174.6cm) and brings it down again continuously 9:40- Escape to cover – Ran quickly 4.5m, dropped to a prone position, got up and run 9:41 back quickly 4.5m continuously 9:45- Sit in one spot – Sitting in a standard metal/plastic chair 9:50 9:50 Leopard crawl – Crawled across the chamber staying as close to the ground as (30 possible secs) 9:53 Leopard crawl – Crawled across the chamber staying as close to the ground as (30 possible secs) 9:56 Leopard crawl – Crawled across the chamber staying as close to the ground as (30 possible secs) 2(REST) 10:00- Rest / Meal (individual meal packs or field rations) preparation/consumption – 12:00 field rations were prepared on request and participants had two full hours to eat the meal & complete surveys 3(ACTIVE) 12:00- Walking on a motorized treadmill – Walked at speed of 2.4km/h at the 12:09 following grades 0%, 5% and 10% with 20kg rucksack 12:09- Walking on a motorized treadmill – Walked at speed of 4km/h at the following 12:18 grades 0%, 5% and 10% with 20kg rucksack 12:18- Walking on a motorized treadmill – Walked at speed of 5.6km/h at the 12:24 following grades 0% and 5% with 20kg rucksack 12:26- Empty jerry can carry – Move two 2.5kg jerry cans, carried them 7.4m, turned 13:10 around and carried them back, turned around and continue 12:30- Empty jerry can carry – Move two 2.5kg jerry cans, carried them 7.4m, turned 12:32 around and carried them back, turned around and continue 12:35- Stretcher carry – Moving two 22.5kg dumbbells and walked from one side of 12:36 the chamber (4.5m) to the other and back continuously 12:38- Stretcher carry – Moving two 22.5kg dumbbells and walked from one side of 12:39 the chamber (4.5m) to the other and back continuously 12:41- Stretcher carry – Moving two 22.5kg dumbbells and walked from one side of 12:42 the chamber (4.5m) to the other and back continuously 12:45- Walking – Walking from one side of the chamber to the other (4.5m one side) 12:47 continuously 12:49- Step up no load – Stepped onto 20cm step and then step back down 12:51 continuously with no load 12:53- Step up no load – Stepped onto 20cm step and then step back down 12:55 continuously with no load 12:55- Drop and fire position – Lying prone with head and shoulders off the ground 13:00 resting on elbows or forearms 13:00- Stacking and tamping – Building fortifications simulations, picked up two 20kg 13:10 sandbags, carried them 7.4m, put them down side by side, walked back empty handed, picked up another two sandbags and placed them beside/on top of the first two. After four sandbags, participants flattened them down with wooden 85 handle (1kg). This was continued for 10 mins. 13:12- Flattening sandbags – Hitting and flattening sandbags with a 1kg wooden handle 13:15 continuously 13:17- Flattening sandbags – Flattening sandbags with foot continuously 13:20 13:20- Stand in one spot 13:25 13:25- Empty ammo can lift – Lift empty ammo can from floor to 123.8 cm high stand 13:27 to back down to the floor continuously 13:30- Full ammo can lift – Lift full 13.7kg ammo can from floor to 123.8 cm high 13:32 stand to back down to the floor continuously 13:35- Dummy drag- dragged an 85kg dummy 5.9m turned around and dragged it back 13:36 continuously 13:38- Dummy drag- dragged an 85kg dummy 5.9m turned around and dragged it back 13:39 continuously 13:41- Dummy drag- dragged an 85kg dummy 5.9m turned around and dragged it back 13:42 continuously 13:45- Step up – stepped onto 20 cm step and then step back down continuously with 13:47 10kg daypack 13:50- Step up – stepped onto 20 cm step and then step back down continuously with 13:52 10kg daypack 13:55- Step up – stepped onto 20 cm step and then step back down continuously with 13:57 20kg daypack 4(REST) 14:00- Rest / Meal (individual meal packs or field rations) preparation/consumption – 16:00 field rations were prepared on request and participants had two full hours to eat the meal & complete surveys 7.3.7 Statistical Analyses The assessment of energy and nutrient data is presented for the 8 hour duration of each treatment, except in section 7.4.2 where data is presented for consumption of nutrients for 24- hours (8-hour duration of the experimental trial plus evening meal/meals and the rest of the 24- hour period). Nutrient data are presented as mean ± standard deviation (SD) or as a percentage of total energy. Energy, macronutrient and micronutrient intakes were compared between the experimental treatments using a linear mixed model that accounts for repeated-measures within participants with condition as fixed factors, visits as repeated effects and with post hoc pairwise comparisons using Bonferroni adjustment to determine statistical significance. Macronutrient intakes were assessed for adequacy in comparison with Dietary Reference Intakes (DRI) recommendations for Average Macronutrient Distribution Ranges (AMDR) for carbohydrates, fat and protein 80 . Water intake was calculated from water consumed as plain water, mixed with a beverage/sports 86 drink or mixed with food. Linear Mixed Models were used to compare differences in urinary and blood biomarkers between experimental conditions; adjusted for total volume of urine when comparing urinary biomarkers. All data were analysed using SPSS Statistics (version 24, 2016; IBM Corporation ®, Armonk: NY, USA). A p-value of ≤0.05 was considered significant. 7.4 Results 7.4.1 Participant Demographics and Anthropometrics Of the 18 CAF participants, 78% were male and 67% were Caucasians. The mean age was 34 ± 11 years, with a mean BMI of 26 kg/m 2 and a mean percent body fat of 23%. The majority of the participants had a university degree (61%) (Table 2). Table 2: Characteristics (demographics and anthropometrics) of the CAF study participants. Characteristics Study Participants (n=18) Age (years) * 34 ± 11 Sex ** Male 14 (78%) Female 4 (22%) Height (cm) * 174 ± 10 Weight (kg) * 79 ± 13 Body Mass Index (kg/m 2)* 26 ± 4 (range: 21-32) Male 26 ± 3 (range: 21-31) Female 27 ± 5 (range: 21-32) Percent Body Fat (%) 23 ± 8 (range: 10-42) Male 20 ± 6 (range: 10-30) Female 33 ± 8 (range: 22-42) Ethnicity ** Caucasian 12 (67%) Asian 3 (17%) African American, Hispanic and South Asian 3 (17%) Education ** High-school graduation 1 (6%) Non-university certificate 6 (33%) University Degree 11 (61%) Marital Status ** Single 12 (67%) Married 5 (28%) Separated 1 (6%) *Mean ± standard deviation (SD); ** n (%) 87 7.4.2 Total Energy and Macronutrient Intake during the 8-hour Experimental Trials Participants consumed approximately 70% (average for the four experimental treatments) of the self-selected field rations during the 8-hour visit (Table 3). For all treatments, average energy intake was 1970 ± 718 kcal/8 hours with total energy from carbohydrates, fat and protein, 59%, 28%, and 13%, respectively, which was within AMDR recommendations (Figure 2). There were no significant differences in energy and macronutrient intakes between the experimental treatments (p> 0.05) (Table 4). Table 3: Energy and macronutrient intakes from self-selected individual meal pack or field rations provided to participants during the 8-hour experimental treatments and for 24-hours. Individual Meal Pack † Energy (kcal) Carbohydrates (g) Total Fat (g) Protein (g) Breakfast 1344 221 41 31 Lunch 1432 224 41 43 Total Available / 8 hours (% of total energy) 2776 445 (64%) 82 (27%) 74 (11%) Dinner/Supper 1317 200 (61%) 39 (26%) 42 (13%) Total Available / 24 hours (% of total energy) 4093 645 (63%) 121 (26%) 116 (11%) AMDR 45-65% 20-35% 10-35% Average consumed ** / 8 hours 1970 295 (59%) 61 (28%) 63 (13%) Average consumed ** / 24 hours 2979 443 (59%) 92 (28%) 99 (13%) †Individual Meal Packs or field rations consisted of a choice of a variety of foods and beverages from 18 menu items (6 breakfast, 6 lunch and 6 dinner/supper), which participants (n=18) pre-selected for their experimental treatments. Once selected, each participant consumed the exact same menu items for each of the experimental treatments (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). 24-hours data included at home post-treatment meals. ** Consumed indicates the average amount of energy and macronutrients eaten during the 8 –hour experimental treatments (in an environmentally controlled chamber) and during the 24-hours (including the at home post-treatment) (as measured using the measured food intake/food waste collection method). AMDR = Average Macronutrient Distribution Range. 88 Energy Intake = 1970 ± 718 kcal/8hours 13% Carbohydrate Total Fat 28% Protein 59% Figure 2: Macronutrient intake as a percentage of total energy Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 8 hours of energy and macronutrient intake by participants for all four randomized experimental treatments (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%), collected using measured food intake/food waste method. The data was averaged for the four treatments. The data was calculated using the energy contribution of 4kcal/g for carbohydrate, protein and 9kcal/g for fat. 7.4.3 Specific Micronutrient Intakes Although intakes of the water-soluble B-vitamins were not significantly different between experimental treatments (p>0.05), vitamin C was highest in temperate in comparison to both the sedentary and cold treatment (p≤0.05), but not different than the hot treatment (Table 4). There were no significant differences between treatments for other micronutrients (including vitamin A, potassium, phosphorus, iron and zinc) (p>0.05), except magnesium where intakes in both cold and sedentary were significantly lower than in the hot and temperate treatments (p≤0.05). Calcium intake was significantly different between the sedentary and hot treatments (p≤0.05), however, there were no differences when sedentary was compared to the cold or temperate treatments (p>0.05). There were no significant differences in sodium intake between experimental treatments (p>0.05), which averaged 3183 ± 1183 mg / 8 hours (mean ± SD) for all four treatments. 89 7.4.4 Caffeine and Water Intakes There was a significant main effect of treatment on caffeine and water intake. Post hoc analysis demonstrated that caffeine intake was highest in cold, followed by temperate, with lowest intakes in the hot and sedentary treatments (p≤0.05) (Figure 3). Water intake was highest in hot, temperate, cold and sedentary treatments (p≤0.05) (Figure 4). Table 4: Comparison of energy and nutrient intake in CAF personnel between 8-hour experimental treatments Nutrient intake per 8 Sedentary Cold Hot Temperate p-value † hours Strenuous Physical Activity ** Energy (kcal) 1920 ± 640 1897 ± 793 2005 ± 795 2055 ± 680 0.56 Carbohydrates (g) 279 ± 105 286 ± 129 298 ± 128 315 ± 118 0.47 Total Fat (g) 62 ± 23 58 ± 25 63 ± 26 61 ± 20 0.44 Saturated Fat (g) 22 ± 9 22 ± 10 22 ± 11 21 ± 8 0.89 Protein (g) 64 ± 20 62 ± 28 64 ± 25 64 ± 20 0.76 Fibre (g) 18 ± 7 19 ± 10 20 ± 9 19 ± 8 0.77 Total Sugar (g) 130 ± 45 132 ± 59 147 ± 59 149 ± 67 0.34 Sodium (mg) 3022 ± 1111 3353 ± 1276 3005 ± 1063 3350 ± 1313 0.25 Potassium (mg) 531 ± 208 474 ± 220 532 ± 200 571 ± 248 0.24 Vitamin A (μg) (RE) 320 ± 266 213 ± 183 248 ± 221 271 ± 243 0.18 a ab b ab Calcium (mg) 435 ± 238 519 ± 283 620 ± 275 530 ± 216 0.017* a a b b Magnesium (mg) 104 ± 43 103 ± 53 133 ± 41 131 ± 50 0.004* Iron (mg) 14 ± 6 14 ± 8 15 ± 7 15 ± 6 0.64 Phosphorus (mg) 272 ± 126 239 ± 117 267 ± 129 289 ± 138 0.28 Zinc (mg) 3.3 ± 1.4 3.3 ± 2.3 3.8 ± 2.2 3.7 ± 1.5 0.51 Vitamin B1 (mg) 0.25 ± 0.15 0.30 ± 0.21 0.33 ± 0.22 0.37 ± 0.20 0.10 Vitamin B2 (mg) 0.23 ± 0.14 1.9 ± 4.8 1.1 ± 3.5 1.2 ± 3.5 0.25 Vitamin B3 (mg) (NE) 8.3 ± 4.6 6.5 ± 4.7 7.7 ± 4.6 8.8 ± 5.7 0.11 Vitamin B6 (mg) 0.59 ± 0.42 0.36 ± 0.27 0.56 ± 0.4 0.47 ± 0.38 0.19 Vitamin B12 (μg) 0.97 ± 1.32 0.64 ± 0.85 0.99 ± 1.08 1.08 ± 1.19 0.23 Folate (μg) (DFE) 96 ± 68 74 ± 72 95 ± 71 107 ± 77 0.24 ‡ a a b b Vitamin C (mg) 88 ± 86 93 ± 123 147 ± 112 184 ± 164 0.02* a b a ab Caffeine (mg) 55 ± 43 109 ± 100 35 ± 48 70 ± 95 0.005* a b c d Water (ml) 1280 ± 536 1843 ± 1050 4148 ± 1086 3440 ± 1071 <0.001* Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 8 hours of nutrient intakes by participants for four randomized experimental treatments (sedentary (21 °C), cold (- 10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Energy and nutrient intake data were collected using measured food intake/food waste method where all consumed and/or non-/partially consumed food and beverage items from the field ration packs were weighed and recorded for each participant. ** Strenuous physical activity consisted of military-type tasks including both supra- and submaximal exercises (e.g. 90 marching, vehicle extrication simulation, stretcher carry, escape to cover, dummy drag, etc. 126 ).Data presented as means ± standard deviation (SD). †Energy and nutrient intake data examined by Linear Mixed Models with Bonferroni adjustment. ‡Vitamin C-fortified drink crystals packets average consumption (average count) were as follows: 0.9 (sedentary), 0.9 (cold), 2.4 (hot), 2.6 (temperate). *p-value is the significance level for differences between the experimental treatments. a,b Values with different superscripts indicate statistical significance differences. RE = Retinol Equivalents; NE = Niacin Equivalents; DFE = Dietary Folate Equivalents. 250 b 200 a,b 150 a 100 a Caffeine (mg/8 hours) 50 0 Sedentary Cold Hot Temperate Strenuous Physical Activity Figure 3: Comparison of caffeine intake in CAF personnel between 8-hour experimental treatments. Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 8 hours of caffeine intake by participants for four randomized experimental treatments (sedentary (21 °C), cold (- 10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Energy and nutrient intake data were collected using measured food intake/food waste method where all consumed and/or non-/partially consumed food and beverage items from the field ration packs were weighed and recorded for each participant. Data presented as mean ± standard deviation (SD) and analyzed using linear mixed models. a,b Plots with different superscripts indicate statistically significant differences (p ≤ 0.05). 91 6000 c 5000 d 4000 3000 b 2000 a Water (ml/ 8 hours) 1000 0 Sedentary Cold Hot Temperate Strenuous Physical Activity Figure 4: Comparison of water intake in CAF personnel (n=18) between 8-hour experimental treatments (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 8 hours of water intake by participants for four randomized experimental treatments (sedentary (21 °C), cold (- 10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Energy and Nutrient intake data were collected using measured food intake/food waste method where all consumed and/or non-/partially consumed food and beverage items from the field ration packs were weighed and recorded for each participant. Data presented as mean ± standard deviation (SD) and analyzed using linear mixed models. a, b, c, d Plots with different superscripts indicate statistically significant differences (p≤0.05). 7.4.5 Total Energy and Macronutrient Intake for post-experimental treatments and for 24-hours There were no differences in energy and macronutrient intake between experimental treatments from the evening meal/meals, where participants consumed an additional 1009 kcal (average for all treatments) in the evening from the self-selected rations (average for dinner rations pack was 1317 kcal) (Tables 3 and 5). Total energy available to consume from three field rations for 24- hours was 4093 kcal but participants consumed 2979 kcal/day (Table 3). 92 Table 5: Comparison of energy and nutrient intakes in CAF personnel during at home consumption of dinner ration pack after the 8-hour experimental treatments. Nutrient intakes Averaged for Post- Post-Cold Post-Hot Post- p- post-experimental post- Sedentary Temperate value* treatments (at experimental (temperate) home) † treatments Post- Strenuous Physical Activity Energy (kcal) 1009 ± 527 1014 ± 701 968 ± 431 1140 ± 528 919 ± 358 0.62 Carbohydrates (g) 148 ± 86 145 ± 114 142 ± 67 170 ± 88 135 ± 54 0.60 Total Fat (g) 31 ± 17 32 ± 20 30 ± 17 32 ± 20 28 ± 12 0.84 Protein (g) 36 ± 17 37 ± 21 33 ± 13 42 ± 17 30 ± 12 0.18 Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 16 hours of energy and nutrient intakes of participants after the 8-hour experimental treatments (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Energy and nutrient intake data were collected using measured food intake/food waste method where all consumed and/or non-/partially consumed food and beverage items from the field ration packs were weighed and recorded for each participant. Strenuous physical activity consisted of military-type tasks including both supra- and submaximal exercises (e.g. marching, vehicle extrication simulation, stretcher carry, escape to cover, dummy drag, etc. 126 ) during the 8-hour experimental treatments. Data presented as means ± standard deviation (SD). †Energy and nutrient intake data examined by Linear Mixed Models with Bonferroni adjustment. * p-value is the significance level for differences between the experimental treatments (post- sedentary, post-cold, post-hot and post-temperate). 7.4.6 Energy Intake in comparison to Energy Expenditure (8-hours and 24- hours) There were no differences in energy intake between the experimental treatments for the 8-hours participants were in the environmentally controlled chamber or for the remaining 16 hours at home post treatments (Table 5, Figure 5). In contrast, energy expenditure was higher in the experimental treatments with strenuous physical activity in comparison with the sedentary treatment (for both 8-hours and 24-hours) (Figure 5). Figure 5 shows a comparison between the energy intake and expenditure for 8-hours and 24-hours, however, complete data analyses for energy expenditure will be presented elsewhere (unpublished data, Mandic et al., University of Toronto). 93 Figure 5: Comparison of energy intake with energy expenditure for 8-hours and for post- treatments (as part of a randomized experimental trial) Energy Expenditure data (unpublished) credit source: Iva Mandic and Dr. Ira Jacobs at Faculty of Kinesiology and Physical Education, University of Toronto. Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 8-hours and 16-hours (total 24 hours) of energy and nutrient intakes of CAF personnel participating in the four experimental treatments (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%). Energy and nutrient intake data were collected using measured food intake/food waste method where all consumed and/or non-/partially consumed food and beverage items from the field ration packs were weighed and recorded for each participant. Strenuous physical activity consisted of military-type tasks including both supra- and submaximal exercises (e.g. marching, vehicle extrication simulation, stretcher carry, escape to cover, dummy drag, etc. 126 ) during the 8-hour experimental treatments. 7.4.7 Urinary and Blood Biomarkers Although, there were no significant differences between experimental treatments for urinary creatinine, potassium and cortisol (p>0.05); urinary urea in the hot treatment was significantly 94 lower than the sedentary treatment (p≤0.05), but not different than the cold or the temperate treatment (p>0.05) (Table 6). Urinary sodium was significantly lower in the hot treatment in comparison to both sedentary and cold treatment (p≤0.05) but not different than the temperate treatment (p>0.05). No differences were found in blood biomarkers between the experimental treatments (p>0.05) (Table 6). Table 6: Comparisons of urinary and blood biomarkers in CAF personnel between 8-hour experimental treatments. Biomarker † Sedentary Cold Hot Temperate p-value Strenuous Physical Activity Urinary Creatinine (mmol/d) 16 ± 4 15 ± 4 15 ± 5 15 ± 6 0.68 a ab b ab Urinary Urea (mmol/d) 406 ± 92 376 ± 113 327 ± 83 359 ± 115 0.03* a a b b Urinary Sodium (mmol/d) 156 ± 56 146 ± 68 97 ± 52 111 ± 68 0.001* Urinary Potassium (mmol/d) 56 ± 16 50 ± 17 48 ± 16 45 ± 19 0.24 Urinary Cortisol (nmol/L) 86 ± 43 73 ± 20 90 ± 59 90 ± 54 0.57 Urea (mmol/L) 5 ± 0.8 5 ± 1.1 5 ± 1.3 5 ± 0.9 0.17 Creatinine (μmol/L) 78 ± 12 79 ± 14 80 ± 15 79 ± 15 0.26 eGFR (ml/min/1.73m^2) 96 ± 9 95 ± 11 92 ± 13 95 ± 12 0.15 Triglycerides (mmol/L) 1.1 ± 0.7 0.9 ± 0.3 0.9 ± 0.3 1 ± 0.6 0.38 Cholesterol (mmol/L) 4.3 ± 0.8 4.1 ± 0.7 4.3 ± 0.8 4.1 ± 0.7 0.19 HDL Cholesterol (mmol/L) 1.3 ± 0.5 1.3 ± 0.4 1.3 ± 0.4 1.3 ± 0.4 0.40 Cholesterol/HDL Ratio (mmol/L) 3.5 ± 0.9 3.3 ± 0.9 3.4 ± 1.0 3.4 ± 1.1 0.38 LDL Cholesterol (mmol/L) 2.4 ± 0.5 2.4 ± 0.6 2.6 ± 0.7 2.3 ± 0.6 0.18 Non-HDL Cholesterol (mmol/L) 2.9 ± 0.6 2.8 ± 0.7 2.9 ± 0.8 2.8 ± 0.8 0.17 Ascorbic Acid (μmol/L) 43 ± 16 42 ± 13 44 ± 14 39 ± 12 0.55 Study participants were Regular Force or Class A Reservists (n=18). The data presented is of 24- hour urinary biomarkers and blood biomarkers (collected the day after the experimental visits (sedentary (21 °C), cold (-10 °C), hot (30 °C) and temperate (21 °C); humidity 30%) of CAF participants. †Urinary and blood biomarker data examined by Linear Mixed Models with Bonferroni adjustment. Data presented as means ± standard deviation (SD) .a,b Values with different superscripts indicate statistical significant differences (p ≤ 0.05); *p-value is the significance level for differences between the experimental treatments. 7.5 Discussion The primary aim of this study was to investigate the acute impact of environmental stress with strenuous physical activity on energy and nutrient intakes from field rations in a convenience sample of CAF personnel. We demonstrated that military personnel consumed only a portion of 95 the ration meals (~70% of the amount provided) under situations of temperature stress even though they had ample time to eat and the meals were prepared on request. Even with an acute challenge of harsh environmental temperatures and strenuous physical activity, there were no differences in energy intakes between experimental treatments. As a result, their energy intake did not increase in relation to increased energy requirements under conditions of temperature stress with strenuous physical activity in comparison to the resting thermo-neutral environment (sedentary (21 °C)). Furthermore, as demonstrated by the total amount of energy consumed post- experimental treatments from the dinner ration packs, participants did not compensate for increased energy expenditure during the experimental treatments by (sufficiently) increasing their energy intake when they had time to eat and conditions of stress (e.g. strenuous physical activity) had subsided. The energy cost as a result of the simulated military tasks performed by participants during the harsh environmental temperature treatments in this experimental trial was above than that from the sedentary experimental treatment (Mandic et al., unpublished data 126 ). Participants were expending less energy in the sedentary treatment (454 kcal), however, there were no differences in energy intakes between experimental treatments with strenuous physical activity in comparison with the sedentary treatment, even though participants were expending more energy during hot, cold and temperate treatments (energy expenditure averaged over the three treatments was 1643 kcal) (Mandic et al., unpublished and for interim analyses, see Jacobs I., 2016) 126,157 . Thus, our results show that participants are likely not meeting the increased energy requirements of strenuous physical activities in harsh environmental temperatures. Previous research has also shown that the energy requirements in temperature extremes are higher than for similar activities conducted in thermo-neutral environments 3,12,76 . This is because in temperature extremes, there is a greater energy cost associated with; 1) thermoregulation 19,74,158 , 2) loss of appetite in heat 3,58,88 , and 3) operating in heavier clothing/footgear in cold climates 19,76 . Our results of insufficient energy intake relative to energy expenditures under conditions of strenuous physical activity in ambient temperature extremes (hot/cold) are comparable to those of other studies, where authors have demonstrated insufficient energy intake relative to energy requirements as a result of both strenuous physical activities and temperature stress 4,9,13,34,89 . This has important implications for energy deficits, 96 weight loss and performance if the study were to be conducted in these temperature extremes (hot/cold) for longer periods of time than was examined in this investigation. It could be that military personnel may compensate for reduced energy intake during the operational activities in harsh environmental temperatures by increasing their intake when time permits and/or when the stresses of operating duties have subsided. However, our measured food intake/food waste from field rations for the complete 24-hours demonstrated that the participants consumed similar amounts of field rations post-treatment and did not compensate for their increased energy expenditures during the strenuous physical activity in harsh temperatures. Fat and carbohydrate catabolism contribute equally to the energy demands of sedentary activities, however, carbohydrates become the fuel of choice for meeting energy requirements as the intensity of exercise increases 12,159 and for maintaining muscle glycogen stores, which are important for sustaining muscular strength and endurance and in the ability to perform physical activities 19,159 . Carbohydrates are also required for optimal thermogenesis under added stress of temperature extremes in addition to the activity cost 12,159 . The results of this study demonstrate that although participants consumed only 70% (averaged for all experimental treatments) of the total carbohydrates provided in the ration packs during 8 hours, the energy contribution from carbohydrates was within the AMDR (45%-65%) and at the top of this range (64%). From these results, we can infer that for prolonged physical performance in temperature extremes, the field rations would likely provide sufficient amounts of carbohydrates if military personnel were to consume the rations completely and eat at-least 3 meals per day. Protein catabolism can contribute 5 to 15 % of the energy needs for prolonged physical activities 3,160,161 ; and although the requirements for protein are similar across the thermo-neutral and temperature extreme conditions 3, protein utilization in the cold might be higher as protein may have a beneficial thermic effect of keeping the body warm 19,162 in contrast to the hot environment, where higher protein intakes might be considered a disadvantage due to increases in excretion of protein breakdown products (urinary and sweat urea) 3,163 . Although we did not see a significant difference in production of urinary urea between the temperature treatments with exercise, previous research has indicated that prolonged cold exposure might lead to an increase in urinary urea excretion 164 . This may have implications for increased protein utilization in prolonged exposure to cold 19,43,162 . Based on the predicted level of protein intake 97 for military personnel (1.61g/kg/day) 5, CAF personnel are likely consuming less than recommended levels of protein from field rations at these 24-hour energy intakes but would meet these protein requirements if more or all of the field ration pack was consumed 11 . Several concerns have been raised regarding the consumption of higher fat diets (as a result of consuming non-ration foods such as high-fat animal foods found in countries with cold climates) and its association with increased cardiovascular risk 19,165 ; but the fat content within the ration packs is generally low and was well-within the acceptable AMDR. Although we did not see an acute impact of ration consumption on cholesterol levels in this study, longer-term consumption (>2 weeks) of low fat intake (as found in the ration packs) has been shown to result in favourable changes in cholesterol levels 100 . The higher caloric density of fat makes it one of the easiest ways to meet increased energy needs during cold weather operations 12 . We did not find differences in fibre intake between the experimental treatments; however, fibre intake in all treatments was lower than the recommended amount of 38g (adequate intake for males) 80 . Since field rations contain on average 31g of fibre likely as a result of low content of fresh fruits and vegetables or high fibre foods 9, it is difficult to obtain the recommended intake of fibre without consumption of the complete ration pack with additional supplementation. Therefore, the consumption of field rations has been postulated to impact soldier’s bowel habits 141 . Studies from other nations have demonstrated diarrhea and constipation with psychological stress to interfere with daily combat performance 141 but whether fibre plays a role in mitigating the bowel issues of military personnel under environmental stress requires further investigation. Although our study was not designed to evaluate the differential requirements for macronutrients under temperature extremes, we did not see a difference in macronutrient preference or intake between the different treatments. This is consistent with previous research indicating that macronutrient preference or intake does not change in settings where participants are able to freely select their foods 9,19,90,91 . We did not see significant differences in intakes of micronutrients when comparing the different treatments, however, participants had a relatively low intake of specific micronutrients because field rations generally provided less than recommended amounts for some micronutrients and because of partial consumption of the field ration, as was seen by previous research from our 98 group and by Hatton et al 9. At present, there is lack of consistent evidence investigating the beneficial effects of micronutrients in enhancing the physical and cognitive performance of military personnel and very few studies have investigated the impact of operating in temperature extremes on micronutrient status 3,9,19,60 . Research indicates that there might be altered micronutrient requirements under temperature extremes as a result of impaired intestinal absorption or increased utilization for maintaining thermoregulation 3,19,61-64 . Additionally, many micronutrients are important components of energy metabolic enzymes and pathways 45 . For example, B-vitamins are involved in the conversion of food to energy and some studies have shown a decrease in physical performance capacity as a result of deficiency in one or more of the B-vitamins 66,67,166 . Limited evidence suggests increased requirements for some B-vitamins as a result of exercise in temperature extremes 3. Previous research from our group has shown that field rations generally provided less than recommended amounts for some of the B- vitamins; depending on the combination of menu items selected and/or intake of field rations by soldiers (Chapter 6). In this study, CAF participants had a low intake of B-vitamins during the 8-hours of experimental trials as well as for 24-hours of consuming field rations only. As a result, military personnel may have less than recommended intakes of B-vitamins while operating in temperature extremes if their intake is compromised, especially in view of increased utilization for these nutrients and incomplete consumption of the field ration pack. Vitamin C intake was relatively high in temperate and hot treatments (as a result of higher intake of vitamin-C fortified drink crystals), in comparison to the cold or sedentary treatments. Whether increasing the intake of vitamin C is beneficial for operating in temperature extremes remains to be confirmed 3,65 . Some studies have indicated a beneficial effect of vitamin C intake on reducing heat stress 3,46,68,167 , however, others remain equivocal in relation to enhancing performance 168 while operating in the hot environment 3,169 . The role of vitamin C in enhancing the immune system 170 remains controversial but it has been suggested that vitamin C may have increased utilization as a result of strenuous physical exertion in prolonged expeditions in cold environments 19,79 . We did not find an acute impact of experimental temperature extremes on plasma ascorbic acid (a nutritional biomarker for clinical status of vitamin C), and in view of the lack of compelling evidence to suggest otherwise, maintaining recommended levels of vitamin C intake pre- and during deployment is likely sufficient to ensure nutrient adequacy in military personnel operating in temperature extremes, at least in an acute setting. 99 The low intake of calcium in the sedentary treatment and of magnesium in both sedentary and cold treatments are likely due to the decreased consumption of specific food items (e.g. chocolate/candy bars, cereals) that provide a considerable source of these nutrients. Although there is limited research examining the impact of exercise in cold environments on magnesium metabolism 19 , studies have indicated increased losses of magnesium via sweat during strenuous physical activities 3,61 , which could have implications for contributing to magnesium deficiency in a cold environment, where soldiers are also prone to sweating 19 . Given that marginal magnesium deficiency can contribute to a reduced work capacity 154,171 and a significant health risk in an individual (e.g. convulsions) 3,172 , ensuring recommended levels of magnesium in field ration packs is likely to be beneficial in sustaining performance. Our results demonstrated that CAF participants consumed higher than recommended amounts of sodium even with partial consumption of ration packs, which is comparable to those found by Hatton et al 9. There has been significant emphasis on reducing the sodium content of Canadian foods and the sodium intake of the Canadian population, however sodium intake recommendations do not take into account the increased amounts of sodium loss from skin through sweat in military personnel operating in the temperature extremes 148 . Although we did not quantify the sodium loss in sweat, we saw significantly less urinary sodium in the hot environment in comparison to the sedentary and cold treatments, which is likely attributed to hyponatremia, a consequence of fluid ingestion and increased sweat production. This may have implications for military personnel being able to tolerate extra sodium under situations of strenuous physical activity in climatic extremes 148 but tolerability may differ upon acclimatization to the environmental extremes 71 . As a result, further research is required to better understand sodium requirements of highly active individuals under conditions of heavy workloads and high sweat rates 3,9 . Considering these micronutrients play a wide variety of roles from acting as antioxidants to energy metabolism, the potential interaction of prolonged exposure to less than recommended intakes of these micronutrients as a result of voluntary anorexia under conditions of environmental stress may lead to impairments in physical and cognitive performance, which are likely to impact the operational readiness of military personnel. As such, it is important to ensure recommended amounts of micronutrients for military personnel operating in climatic extremes, especially in view of voluntary anorexia. 100 Intakes of caffeine were low in the hot environment, likely as a result of low intakes of hot beverages (e.g. coffee, cappuccino) from the ration packs. Considering the role of caffeine as a possible intervention strategy for enhancing cognitive and physical performance to sustain operational effectiveness 173 , further research in the use of caffeine for military personnel while operating in temperature extremes is required. It is well established that adequate hydration levels have significant impacts on health and performance of military personnel; therefore maintaining adequate intakes of water is crucial during operations in temperature extremes with strenuous physical activity. In this study, participants consumed significantly less water in the cold treatment in comparison to the hot and temperate environments. This may have implications for dehydration in the cold environment as a result of increases in fluid loss via sweating through heavy clothing or respiratory water losses in combination with increased metabolic activity 19,77,158 . Although other studies have indicated a strong correlation between water and food consumption 100,174 , the results from this study showed a significant difference in water intake between experimental treatments even though energy intake did not differ. Factors other than the availability of food are likely to influence water consumption while operating in climatic extremes. These factors may include decreased thirst sensation, the activity level or the respiratory losses of water under environmental stress 19,43,77 . 7.6 Conclusions Although our study is limited by a small sample size and was not designed to assess the impact of prolonged strenuous physical activities in temperature extremes on nutrient intakes, we demonstrated that, in comparison with energy consumed during the sedentary treatment, military personnel had similar energy and macronutrient intakes from field rations, even with an acute challenge of increased physical activity and temperature stress in this experimental trial designed to simulate field conditions (hot, cold and temperate) with strenuous physical activity. Our study is the first to demonstrate in a convenience sample of CAF personnel that, even where CAF personnel had ample time to consume the food and where the food was prepared on request, participants did not eat the ration packs in their entirety. As a result, there was a gap between the amount of food provided versus the amount that was consumed, which would be further compounded in the field due to conditions such as load carriage, cooking and prolonged exposure to temperature extremes. These results likely underestimate the implications for not 101 meeting the energy requirements of CAF personnel under metabolically challenging operations if the study were to be conducted for a longer period of time, thereby contributing to voluntary anorexia (well-documented in the military) 5,18 . Additionally, our study also demonstrated that the energy intake was less than the expenditure for harsh environmental temperatures for 24- hours, thus, indicating that military personnel did not compensate for reduced energy intake during the experimental treatments even when they had time to eat and the stresses of strenuous physical activities in harsh environmental temperature had subsided (i.e. post-experimental treatment at home). Although, short-term field operations are not likely to lead to micronutrient deficiencies unless there is pre-existing depletion of stores, less than recommended intakes of micronutrients may have profound impacts on both physical and cognitive performances in a longer term setting 19 . Further research is required to better understand the relative macronutrient and micronutrient needs to optimize performance. 7.7 Acknowledgements This study was part of a larger military feeding project, which was funded by a Defence Research and Development Canada (DRDC) research contract (#2013-075) awarded to the University of Toronto. Mavra Ahmed was also supported by a Canadian Institute of Health Research (CIHR) Strategic Collaboration in Public Health Policy Fellowship and an Ontario Graduate Scholarship during her candidature. The authors would like to acknowledge the assistance of the DRDC staff involved in recruiting participants and data collection, the representatives of the Surgeon General of the Canadian Armed Forces co-housed within the DRDC research centre, and the Canadian Forces Environmental Medicine Establishment (CFEME) for provision of experimental medical support. The authors thank the CAF personnel of the DRDC, CFEME, and Dennison Armories, Toronto, Ontario for volunteering to participate in this study. 7.8 Author Contributions Ira Jacobs was the principal investigator responsible for the research contract-funding proposal and to whom the funding was awarded that supported this research. Mavra Ahmed, Iva Mandic, and Len Goodman performed the data collection. Mavra Ahmed conducted the statistical analysis of the data presented and was responsible for the draft of the manuscript. Wendy Lou 102 helped with the statistical analysis and interpretation of the data. Mavra Ahmed, Iva Mandic, Len Goodman, Ira Jacobs, and Mary L’Abbé were involved in study conception and design, critical revision of the manuscript, and statistical interpretation. Mary L’Abbé , Ira Jacobs, and Len Goodman were involved in supervision. All authors have reviewed and approved the final manuscript. 7.9 Conflicts of Interest The authors declare no conflict of interest. 7.10 Addressing Links to Next Chapter This study investigated the energy and nutrient intakes in experimental treatments of demanding physical activities under extreme environmental temperatures in comparison with the sedentary treatment. However, in this study, participants were conducting the activities for a total of 4 hours (2 X 2 hours of circuits), interspersed with 4 hours (2 X 2 hours) of rest periods. Field rations were prepared on request for the participants and they had ample time to consume the food. In the next Chapter, we will assess additional challenges of limited time to eat and prepare food in relation with conducting demanding operations for prolonged period (5-days compared to the 4 hours in the chamber) during an extreme environmental temperature (winter weather field training exercise). 103 Chapter 8 Dietary Intakes of Canadian Armed Forces Personnel Consuming Field Rations During a Winter Weather Field Training Exercise This study is under review with co-authors. This study addressed objective # 4 & 7 of my thesis, to: Assess energy and nutrient intakes of Canadian Armed Forces personnel during a winter weather field training exercise. This Chapter also addresses the sub-objective: to explore nutrient intakes of male and female military personnel. Student’s contribution: I was involved in developing the experimental protocol for this study in collaboration with Iva Mandic, Dr. Len Goodman, Dr. Ira Jacobs and my supervisor, Dr. Mary L’Abbé . I had help from Ingrid Smith, Iva Mandic, Wendy Sullivan-Kwantes and Dr. Len Goodman with food waste data collection in the field. I entered and analyzed the data independently. Elliot Desilets (supervisor Dr. Peter Jones) conducted the doubly-labelled water measurements of energy expenditure. I independently learned the data analysis and reviewed it with Dr. Wendy Lou to ensure my analyses and interpretation of the data was accurate. I independently prepared a draft of the manuscript prior to engaging my co-authors in reviewing and revising the manuscript for subsequent publication. 104 Dietary Intakes of Canadian Armed Forces Personnel Consuming Field Rations during a Winter Weather Field Training Exercise Mavra Ahmed 1, Iva Mandic 2, Elliot Desilets 3, Ingrid Smith 4, Wendy Sullivan-Kwantes 4, Wendy Lou 5, Peter Jones 3, Len Goodman 4, Ira Jacobs 2 and Mary L’ L’Abbé 1 1 Department of Nutritional Sciences, University of Toronto, Toronto, M5S 3E2, Canada; [email protected] (M.A.); [email protected] (M.L.) 2 Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, M5S 2W6, Canada; [email protected] (I.M.); [email protected] (I.J.) 3 Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, R3T 6C5, Canada; [email protected] ; [email protected] 4 Defence Research and Development Canada – Toronto Research Centre, Toronto, M3K 2C9, Canada; [email protected] (I.S.); [email protected] (W.SL.); [email protected] (L.G.) 5 Dalla Lana School of Public Health, University of Toronto, Toronto, M5T 3M2, Canada; [email protected] * Correspondence: [email protected]; Tel.: +1-416-978-7235 Key words: energy intake, nutrition, military training, cold environment 8.1 Abstract Introduction: Dietary Reference Intakes (DRIs), designed for the healthy Canadian adult population, are used by the Canadian Armed Forces (CAF) to guide the energy content of field rations provided to personnel deployed to the field for training or operations. The high energy expenditures likely to occur under such conditions are not adequately considered. The nutrient intakes of CAF personnel may be further compromised in light of anecdotal reports that their individual meal packs (IMPs) are often partially eaten or portions discarded. The objective of this study was to assess energy and nutrient intakes of CAF personnel during a winter weather field training exercise. Methodology: Dietary intake of a convenience sample of 18 CAF Class A Reservists (n= 9 male + 9 female) (mean age 32 y) was assessed using the 4-day daily measured food intake/food waste collection method. The nutritional content of field rations was provided by CAF 105 Directorate Food Services and inputted into ESHA © Food Processor software to obtain a detailed nutrient profile of participants’ dietary intakes. Results: Average energy intake was 2028 kcal/day, with 53% of total energy from carbohydrates, 32% from fat, and 16% from protein, percentages that are within the acceptable DRI Average Macronutrient Distribution Range. Mean energy intake was below the energy expenditure (4917 kcal/day) as measured using the doubly-labelled water technique. As a result of an energy deficit of 2889 kcal, participants had a significant weight loss of 2.7% during the 5- day field training exercise. Conclusion: Participants in the winter weather field training exercise demonstrated voluntary anorexia, as their energy intake was lower than the energy provided from field rations and they had insufficient energy intake in comparison with their energy expenditure, thereby resulting in significant weight loss. Such results have important implications for impairment of performance and health under longer duration operations. 8.2 Introduction Military personnel frequently encounter metabolically demanding physical activities during training or deployment 19,43 . The physical demands encountered by military personnel can range from sedentary to as high as 10,000 kilocalories (kcal) per day in some cases 12,23 . Research has also shown that energy requirements in climatic extremes can be more than that required if those activities were conducted in thermo-neutral environments 2,3,12,76 . This is likely due to the added stress of extreme environmental temperatures on energy requirements. Exposure to extreme cold increases energy requirements of military personnel due to the increased metabolic rate associated with functioning in heavier clothing/boots, extra demands on physical activity as a result of snow/ice-covered terrain and additional heat production to regulate body temperature 19,43,75,77 . Dietary Reference Intakes (DRIs), designed for the healthy Canadian adult population 80 , are used to guide the energy content of Canadian Armed Forces (CAF) field rations or Individual Meal Packs (IMPs) 11 . These rations are intended to be nutritionally sufficient for standard military operations for extended time periods, however they may not adequately consider the high-energy expenditures that military personnel encounter during training and/or combat operations 11,36 . Although, additional food may be provided in conditions where greater 106 sustenance is warranted (e.g. conditions of climatic extremes), these are at the discretion of the unit commander’s authorization and currently have not been set empirically, based on measured nutritional or physiological requirements 11 . As a result, it is unknown whether the current nutrient composition of the CAF field rations is sufficient to meet the energy requirements of military personnel in harsh environmental temperatures and whether there is a requirement for additional sustenance. Operating in temperature extremes frequently leads to a gap between the amounts of food provided versus the amount that is consumed 15 . This challenge is further compounded by factors such as palatability/variety of rations provided, cooking method/time required for food preparation, and load carriage 5,9,11,152 . The nutrient intakes of CAF personnel may be further compromised in light of anecdotal reports that their IMPs are often partially eaten or portions discarded. As repeatedly demonstrated in literature, these factors play a role in contributing to voluntary anorexia (defined as failure to consume foods that are offered or readily available under situations of extreme stress 5), which can have negative psychological and physiological consequences, thereby impacting operational readiness and performance 5,15,18 . Hence, adequate nutrition intake during exercise in harsh environmental conditions is critical towards maintaining energy balance in order to optimize physiological and psychological functional capacity 13 . Investigating the effects of extreme cold on operational requirements is challenging in real-life settings and thus has not been well defined in a population of CAF personnel. The majority of the studies conducted with Canadian military personnel in extreme cold environments did not accurately assess energy and nutrient intakes coupled with accurate measures of energy expenditure 9,17 . Although, one of those studies used the gold standard in assessing energy expenditure (doubly-labelled water) 17 , the use of self-report dietary assessment method in this study to assess energy intakes limited precise estimates of energy deficit 17 . Therefore, it is difficult to assess the extent to which energy deficits observed during field operations can be attributed to energy intake/expenditure. Consumption of local and/or supplemental food as well as having scheduled time to eat were also identified as factors in these studies that are likely to impact the accurate assessments of energy intake. Thus, the extent to which energy deficits can be attributed to accurate assessments of energy deficits from field rations and expenditure are unknown. 107 Thus, the primary objective of this study was to accurately assess energy and nutrient intakes, using a measured food intake/waste collection method, of a convenience sample of CAF personnel during completion of a 5-day basic combat training course under winter weather conditions where accurate assessments of energy expenditure were made. The secondary objectives of this study included assessments of habitual dietary intakes using a food frequency questionnaire and exploring comparisons of dietary intakes between male and female CAF military personnel. 8.3 Methods 8.3.1 Study Participants A convenience sample of 20 CAF participants from Class A Reservists initially volunteered to participate in this study. Of the 20, 18 completed the exercise and 2 dropped out due to medical reasons. This research was conducted during a regularly scheduled CAF Basic Military Qualification Training Course at Canadian Forces Base (CFB) Meaford during January 26 th -31 st , 2015. All participants provided written informed consent to participate in this study. Research ethics review boards at the University of Toronto (#31260) and DRDC (#2015-001) approved the study protocol. 8.3.2 Experimental Protocol This is an observational cross-sectional study where the pre-study phase involved the consent process, completion of the Physical Activity Readiness Questionnaire-Plus (PAR-Q+) 175 and completion of a food frequency questionnaire on habitual dietary intakes, collection of demographics and anthropometric measurements, and measurement of aerobic capacity and body composition, immediately before the study phase period. During the 5-day training phase, four days of data collection on dietary intakes were completed using a measured food intake/food waste method. Energy expenditure was measured using the doubly-labelled water technique (study details published elsewhere 176,177 ). The post-study phase consisted of measurements of body weight, height and body composition as well as completion of end of study questionnaires (e.g. mood questionnaire 178 ). An overview of the study protocol is shown in Figure 1 and a detailed description of this study can be found in the technical report prepared by University of Toronto for Defence Research and Development Canada (DRDC) 176 . 108 Figure 1: Winter Weather Field Training Exercise Experimental Protocol. 1PARQ+ = Physical Activity Readiness Questionnaire; 2CDHQII = Canadian Diet History Questionnaire II is a food frequency questionnaire used to assess ‘habitual’ dietary intakes of CAF military personnel; 3Body composition measurements were assessed using the deuterium isotope dilution procedure; 4POMS questionnaire is a profile of moods survey; 5Dietary intake from field ration consumption was assessed using a measured food intake/waste collection method, 6Energy expenditure was measured by doubly-labelled water (DLW) and 7End of study questionnaire included questions on body weight maintenance. 8.3.3 Demographic and Anthropometric Assessments Participants were asked to complete a questionnaire on demographics that included information on ethnicity and education level. Anthropometric assessments included measured height, weight, and body fat percentage. Body weight and height were measured before and after the training exercise, without shoes and with participants wearing their standard issued military clothing, using standard, calibrated equipment (stadiometer and weight scales (HealthOMeter Continental Scale Corp., Bridgeview ILL, USA). Body mass index (BMI) was calculated as the body weight (kg) divided by the height (m) squared. 8.3.4 Energy Expenditure and Body Composition Assessments This manuscript focuses on the energy and nutrient intakes of a convenience sample of CAF personnel completing a basic military qualification-training course during winter weather field training exercise. Although, the energy expenditure and body composition data are not being 109 presented in this manuscript, we used the “gold standard” for field determinations of energy expenditure, i.e. the doubly-labelled water technique that involved collection of saliva and urine. Body composition (including percent body fat) was assessed using the deuterium isotope dilution procedure. Further details can be found in the technical report prepared by University of Toronto for DRDC 176 and an MSc thesis prepared by Elliot R. Desilets 177 . 8.3.5 Dietary Intake Assessments Habitual dietary intakes are defined as intakes that participants would ‘regularly’ consume when not eating field rations or during training and/or operations. Habitual dietary intakes were assessed using the Canadian Diet-History Questionnaire II (C-DHQII) 179 , which is a food- frequency questionnaire that measures the frequency of the food/beverage items that are ‘habitually or usually’ consumed. Participants completed the C-DHQII during the pre-study phase and all data were analyzed using food composition data for Canada based on the Canadian Nutrient File 2015 data 180 . For the duration of the training exercise, participants selected their choice of Individual Meal Pack (IMP) and Light Meal Combat (LMC) rations and had a choice of 6 rations per meal type (e.g. 6 Breakfast, 6 Lunch and 6 Dinner). Participants were asked to refrain from the consumption of foods other than those found in rations as well as dietary supplements and performance enhancers. However, if they did so, participants were asked to provide all wrappers for any foods/beverages they consumed outside of selected IMPs/LMCs. The IMPs and LMCs contain pre-packaged, pre-labelled food and beverage items (e.g. sliced apples, bread, coffee, breakfast sausages etc.). The IMPs contained mostly meal entrees (e.g. sliced apples, breakfast sausages, bread), whereas the LMCs are composed of easy-to-eat snacks (e.g. energy bars, sports drinks, chocolate bars). The foods and beverages within these rations are of precisely known quantity and nutrient composition. Although, participants could only consume the beverages (e.g. sports drink, coffee, tea, vanilla cappuccino) provided within the rations, they were able to have water ad libitum. Due to logistical issues, water intake was not measured. Dietary intake of the 18 male and female CAF participants during the study phase was assessed using measured food intake/waste method (considered the current gold standard in dietary assessments), on the first four days of the training course. Prior to the field training, participants 110 were provided with plastic bags labelled with their study id and date and were required to return all partially consumed/ unconsumed food items as well as containers of all consumed food items. If participants shared food (e.g. chocolate bar), participants were asked to provide half the wrapper of that item, whereas the participant who shared that item would provide the other half of the wrapper. In the scenario of shared items, study coordinators estimated intake of that particular item as equally distributed among participants. Study coordinators collected the food waste bags at the end of each day. Each day, all unconsumed and/or partially consumed food and beverage items were weighed and recorded by study coordinators (MA, IM and IS) to the nearest gram or milliliter, using a standard food scale (PrepTech, PT-800, Newport Beach, CA). If the container was empty, the item was considered fully consumed. The measured food intake/food waste was calculated from the amount unconsumed subtracted from the known quantity of each menu item selected during the field training. The nutrient values for the IMP and LMC field rations were provided by CAF Directorate of Food Services and entered into the nutrient software program (ESHA © Food Processor SQL, version 10.13.1, 2013, ESHA Research, Salem, OR) by a study coordinator (MA). 8.3.6 Statistical Analyses Energy and nutrient intake data are presented as mean ± standard deviation (SD) or as a percentage of total energy. Macronutrient intakes were assessed for adequacy in comparison with DRI recommendations for Average Macronutrient Distribution Ranges (AMDR) 80 . The study was not powered to see a difference in nutrient intakes between male and female military personnel; however, this study explored this comparison as a secondary objective. Energy and nutrient intakes from field rations were compared between males and females using a linear mixed model, adjusted for Body Mass Index (BMI) and energy. Data on average sodium intakes of the Canadian population were obtained from Garriguet et al. 147 . All data were analysed using SPSS Statistics (version 24, 2016; IBM Corporation ®, Armonk: NY, USA). A p-value of ≤0.05 was considered significant. 111 8.4 Results 8.4.1 Environmental Conditions During Study Phase Weather information was collected daily during the duration of the field study from January 26 th -January 30 th , 2015. The average mean temperature was -11°C, with a minimum of -22°C, a maximum of -2°C, and a low wind-chill of -25.9°C. 8.4.2 Study Participants Physical characteristics of the 18 participants that completed the study are presented in Table 1 . During the 5-day study period, body mass was significantly reduced by 2.7% (-2.05 ± 1.09 kg) and body mass index (BMI) was significantly reduced by 2.7% (-0.81 ± 0.39 kg/m 2) ( p≤0.05). There was a 4% decrease in body fat percentage ( p≤0.05) 176,177 . Table 1. Demographics and anthropometrics of winter weather field training exercise study participants (n=18) † Demographics and Anthropometrics All (18) Males (9) Females (9) Age (years) ** 33 ± 7 31 ± 6 35 ± 9 Height (m) ** 1.73 ± 0.08 1.78 ± 0.07 1.68 ± 0.06 Body Mass Pre-Study (kg) ** 77.7 ± 9.9 78.1 ± 9.2 77.3 ± 10.9 Body Mass Post-Study (kg) ** 75.7 ± 9.5 * 76.1 ± 8.9 * 75.2 ± 10.6 * BMI Pre-Study (kg/m 2)** 26.1 ± 3.9 24.6 ± 2.3 27.5 ± 4.7 BMI Post-Study (kg/m 2)** 25.3 ± 3.7 * 23.9 ± 2.1 * 26.7 ± 4.4 * Body Fat (%) Pre-Study 27.8 ± 7.3 27.1 ± 7.7 28.6 ± 7.9 Body Fat (%) Post-Study 23.8 ± 8.4 * 23.9 ± 7.9 * 24.6 ± 9.6 * Ethnicity ‡ Caucasian 16 (88%) 7 (78%) 18 (100%) Asian 1 (6%) 1 (11%) 0 (0%) African American 0 (0%) 0 (0%) 0 (0%) Hispanic 0 (0%) 0 (0%) 0 (0%) Other 1 (6%) 1 (11%) 0 (0%) Education ‡ Less than high school 0 (0%) 0 (0%) 0 (0%) High-school graduation 5 (28%) 3 (33%) 2 (22%) 112 Non-university certificate 10 (55%) 5 (56%) 5 (56%) University Degree 3 (17%) 1 (11%) 2 (22%) Marital Status ‡ Single 4 (22%) 4 (44%) 0 (0%) Married 11 (61%) 5 (56%) 6 (67%) Separated 3 (17%) 0 (0%) 3 (33%) †Study Participants (n=18) were Class A Reservists, completing a CAF basic military qualification course during a 5-day winter weather training exercise (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). ** Mean ± Standard Deviation (SD), ‡n (%), * Significantly different from pre-study, p ≤ 0.05. 8.4.3 Energy and Nutrient Intakes from Field Rations During Winter Weather Field Exercise Participants were provided with a total of 5685 kcal/day (4560 (IMP) + 1125 (LMC) kcal/day) of which they consumed 36% of the energy available from both IMP+LMC and 45% of the energy available from IMPs only (Figure 2). Average energy intake was 2028 ± 1003 kcal/day, with 53% of total energy from carbohydrates, 32% from fat, and 16% from protein, which were within the AMDR values (Figure 3, Table 2). Total sodium intake was 3060 ± 1468 mg/day while total sugar intake was 150 ± 72 g/day (Table 3). Intakes of additional nutrients are shown in Table 3. Although this study is not powered to detect differences between energy and nutrient intakes of males and females military personnel, unadjusted analyses demonstrated that males had significantly higher intakes of saturated fat, protein, vitamin A and sodium in comparison to females ( p≤0.05). However, this relationship was not significant after adjustment for BMI and energy. No other nutrient intake differences were found between males and females (Table 4). 113 6000 LMC 1 5000 1125 4000 3000 IMP 2 2000 4560 Energy (kcal/day) IMP 2+LMC 1 1000 2028 0 Field Ration Provided Field Intake Figure 2: Total energy intake per day from field rations selected by participants compared to consumed energy intake Study Participants (n=18) were Class A Reservists, completing a CAF basic military qualification course during a 5-day winter weather training exercise (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). Field Ration refers to the total energy content available from individual meal packs (IMPs) 2 (4560 kcal) and light meal combat (LMC) 1 (1125 kcal) rations (calculated using the nutrient values provided by CAF Directorate Food Services), whereas field intake (2028 kcal) refers to the energy portion consumed by participants (assessed for 4 days using the measured food intake/food waste collection method). Data presented as means ± standard deviation (SD). Table 2: Average energy and macronutrient composition of field rations selected and consumed by winter weather field training exercise study participants Field Rations Energy (kcal) Carbohydrates (g) Total Fat (g) Protein (g) Breakfast 1435 221 45 49 Lunch 1587 227 50 61 Dinner 1538 234 44 55 IMP* 4560 682 (59%) 139 (27%) 165 (14%) LMC** 1125 203 (72%) 25 (20%) 35 (12%) Selected/day 5685 885 (62%) 164 (26%) 200 (14%) Average Consumed/day 2028 271 (53%) 71 (32%) 79 (16%) AMDR † 45-65% 20-35% 10-35% Study Participants (n=18) were Class A Reservists, completing a CAF basic military qualification course during a 5-day winter weather training exercise (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). Breakfast, Lunch and Dinner values correspond to the average of 6 field rations / meal type. Average Consumed/day refers to the amount participants consumed of the total available. 114 Field dietary intake assessed for 4-days using measured food intake/ food waste collection method. IMP = Individual Meal Pack = IMP; LMC = Light Meal Combat = LMC; AMDR = Average Macronutrient Distribution Ranges 80 160% Field Intake 140% Light Meal Combat (LMC) 120% Individual Meal Pack (IMP) 100% LMC 80% 60% 40% LMC Macronutrients as % of total energy IMP Field Intake 20% IMP Field Intake LMC IMP Field Intake 0% S C S C S C Carbohydrates Fat Protein Figure 3: Comparison of macronutrient intake as percentage (%) of total energy for CAF personnel during a winter weather field training exercise between field rations selected (S) and consumed (C). Study Participants (n=18) were Class A Reservists, completing a CAF basic military qualification course during a 5-day winter weather training exercise (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). Field rations consisted of individual meal packs (IMPs) and light meal combat (LMC) rations; field intake refers to the macronutrient portion consumed by participants. Field dietary intake assessed for 4 days using measured food intake/ food waste collection method. Data presented are macronutrient intakes as percent (%) of total energy. 115 Table 3: Energy and nutrient intakes from field ration consumption during the winter weather field training exercise (n=18). Nutrient Intakes from Field Rations Energy (kcal/day) 2028 ± 1003 Carbohydrates (g/day) 271 ± 131 Total Fat (g/day) 71 ± 41 Saturated Fat (g/day) 28 ± 13 Protein (g/day) 79 ± 38 Fibre (g/day) 19 ± 11 Sugar (g/day) 151 ± 72 Vitamin A (μg /day) 250 ± 132 Vitamin C (mg/day) 107 ± 58 Calcium (mg/day) 413 ± 208 Iron (mg/day) 14 ± 6 Sodium (mg/day) 3060 ± 1468 Study Participants (n=18) were Class A Reservists, completing a CAF basic military qualification course during a 5-day winter weather training exercise (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). Field dietary intake assessed for 4 days using measured food intake/ food waste collection method. Intakes from field rations refer to consumption of foods and beverages from selected individual meal packs and light meal combat field rations. Data presented as means ± standard deviation (SD). Table 4: Comparison of daily intakes of selected nutrients from field rations between male and female study participants during the winter weather field training exercise Nutrient Males Females p-value p-value (BMI- (n=9) (n=9) (unadjusted) and energy adjusted) Energy (kcal/day) 2430 ± 1082 1626 ± 778 0.09 0.20 ** Carbohydrates (g/day) 317 ± 133 224 ± 118 0.14 0.16 Total Fat (g/day) 87 ± 49 55 ± 26 0.10 0.51 Saturated Fat (g/day) 34 ± 14 22 ± 9 0.04 * 0.06 Protein (g/day) 97 ± 43 60 ± 23 0.04 * 0.08 Fibre (g/day) 22 ± 9 17 ± 13 0.36 0.12 Total Sugar (g/day) 177 ± 64 124 ± 72 0.12 0.42 Vitamin A (μg/day) 310 ± 79 190 ± 151 0.05 * 0.25 Vitamin C (mg/day) 118 ± 56 95 ± 60 0.43 0.49 Calcium (mg/day) 465 ± 188 360 ± 224 0.30 0.25 Iron (mg/day) 17 ± 7 12 ± 4 0.06 0.42 Sodium (mg/day) 3777 ± 1405 2343 ± 1204 0.04 * 0.11 Study Participants (n=18) were Class A Reservists completing a CAF basic military qualification course (average temperature -11°C, with a minimum of -22°C, a maximum of -2°C). Field dietary intake 116 assessed for 4 days using measured food intake/ food waste collection method. Comparison of dietary intakes by males (n=9) and females (n=9) CAF military personnel consuming self-selected field rations during the 5-day winter weather field training; Data analyzed using Linear Mixed Models with gender as a fixed factor - unadjusted and adjusted for body mass index (BMI) and energy, using the Akaike’s second order information criterion (AICc). Data presented as means ± standard deviation (SD); *Significant p-value (p ≤0.05); ** Energy intake is BMI adjusted only. 8.4.4 Measured Energy Deficits The mean total daily energy expenditure, as measured using doubly-labelled water by our research team, in participants was 4917 kcal/day (range; 3761-5985 kcal/day) (for complete analyses, see Jacobs et al., 2015 and Desilets, E., 2015) 176,177 . The energy deficit measured in this study was 2889 kcal/day (energy expenditure of 4917 kcal/day – energy intake of 2028 kcal/day). 8.4.5 Habitual Energy and Nutrient Intakes assessed by the Canadian Food Frequency Questionnaire (CDHQ-II) Prior to study initiation, habitual dietary intakes were examined using a Canadian Diet History Food Frequency Questionnaire. Participants’ energy intake was estimated to be 1961 ± 653 kcal/day, with 48% of total energy from carbohydrates, 35% from fat and 17% from protein, which were within the AMDR values. Sodium intake was 3199 ± 1126 mg/d, while total sugar intake was 101 ± 40 g/day (Table 5). Intakes of additional nutrients are shown in Table 5. Although this study is not powered to statistically test for differences between males and females, exploratory analyses indicated no differences in energy or nutrient intakes between males and females (p>0.05) (Table 5). Sodium intakes from habitual diets (3199 mg) and from field ration (3060 mg) consumption were similar to that of the Canadian population (3200 mg), but higher than the DRI recommendation (1500 mg) and Tolerable Upper Limit (2300 mg) (Figure 4). Table 5: At home dietary intakes of participants prior to the start of the winter weather field exercise. Nutrient Dietary Intake at Males (n=9) Females Gender Home (n=9) Comparison (n=18) p-value (unadjusted) Energy (kcal/day) 1961 ± 652 2181 ± 826 1740 ± 337 0.16 117 Carbohydrates 225 ± 66 246 ± 83 204 ± 37 0.18 (g/day) Total Fat (g/day) 78 ± 30 86 ± 35 69 ± 22 0.24 Saturated Fat (g/day) 25 ± 10 28 ± 12 22 ± 6 0.21 Protein (g/day) 87± 44 100 ± 56 75 ± 24 0.25 Fibre (g/day) 18 ± 8 20 ± 11 16 ± 5 0.41 Sugar (g/day) 101± 40 109 ± 52 92 ± 22 0.39 Vitamin A (μg /day) 348 ± 228 438 ± 270 257 ± 138 0.09 Vitamin C (mg/day) 116 ± 65 122 ± 80 110 ± 49 0.69 Calcium (mg/day) 987 ± 563 1132 ± 720 841 ± 327 0.29 Iron (mg/day) 16 ± 6 17 ± 8 15 ± 4 0.50 Sodium (mg/day) 3199 ± 1125 3604 ± 1395 2794 ± 613 0.13 Study Participants (n=18) were Class A Reservists. Dietary intakes at home refer to consumption of food and beverages normally and/or regularly consumed when not on training or deployment. Dietary intake data at home was assessed using the Canadian-Diet History Questionnaire II (CDHQ-II) during the pre- study phase; Data analyzed using Linear Mixed Models for independent samples and presented as means ± standard deviation (SD); p-value is presented as unadjusted. 5000 4500 4000 3500 3000 1 2500 UL 2300mg 2000 1500 SodiumIntake (mg/day) 1000 500 0 Usual Intakes Field Ration Canadian Adequate Intake 2 Intakes Population (DRI) Figure 4: Comparison of sodium consumed from habitual diets at home and self-selected field rations during the winter weather field training to that of the Canadian population Study Participants (n=18) were Class A Reservists. Dietary intakes at home refer to consumption of food and beverages normally and/or regularly consumed when not on training or deployment. Dietary intake data at home was assessed using the Canadian-Diet History Questionnaire II (CDHQ-II) during the pre- study phase. Field ration intake assessed for 4 days using measured food intake/ food waste collection method. Data presented as means ± standard deviation (SD). Sodium intake of the Canadian population 118 obtained from Garriguet et al. (2007) 147 . Dietary Reference Intake (DRI 2) (Adequate Intake) 1500 mg, whereas the black line is the Tolerable Upper Limit (UL) 1 of 2300 mg/day. 8.5 Discussion The present study assessed the energy and nutrient intakes of a convenience sample of CAF Reservists personnel during a winter weather field training exercise. Our primary findings of low energy and nutrient intakes and a significant loss (2.7%) of total body mass with a 4% decrease in body fat percentage after the 5-day training exercise demonstrated a significant energy deficit where metabolic requirements (energy expenditure measured in the winter weather field training exercise was ~4900 kcal; data presented elsewhere 126,176,177 ) were higher than intakes. As a result, our participants exhibited voluntary anorexia, as also seen in earlier studies 5,15,18,91,100 . Although the environmental temperatures sustained by participants were higher than those reported in the study by Jones et al. 17 , where the study participants (CAF personnel) experienced an average temperature of -30 °C, the temperatures are comparable to those of other reported cold weather energy assessments experiments with military personnel 90,91 . Hoyt et al. investigated the energy requirements of troops where the temperatures ranged from -15 °C to +13 °C 90 , while in a study by King et al., the temperatures averaged -20 °C 91 . During the winter weather field training, the participants’ loss of total body mass post-study is similar to other research in this area, which consistently reported energy deficits and weight loss during field operations 90,91,100 . Infantry personnel demonstrated a 1.7% to 2.8% body weight loss during a 10-day field study in Alaska 91,100 , comparable to the 2.7% body mass lost in our 5- day study. In contrast, a study by Jones et al. 17 , measured a loss of 0.9% body weight in soldiers on a 10-day cold weather military field operation, however, in this latter study, soldiers consumed about 60% of the rations provided, although dietary intake data were collected using self-reported food records, which may suggest potential misreporting compared to the studies conducted in Alaska 100 , where soldiers consumed about 40% to 70% of the rations provided and dietary intake data was collected using 24-hour recalls confirmed with food waste (more accurate measures of dietary assessment). 119 The trade and experience of a soldier may also play a role in contributing to consumption of sufficient energy in relation to their energy expenditures, where soldiers with more trade experience and/or high levels of physical fitness are likely to minimize their energy deficits by ensuring adequate energy intake. However, weight losses ranging from 3% to 7% of initial body weight during 14-18 days have also been documented in US Rangers operating in a variety of environmental temperatures and terrain 24 . Similarly, special operations soldiers’ also experienced a 1.5% to 5.6% weight loss in 28 days, depending on the amount of energy consumed in relation to energy expenditure 30 . Longer duration studies have also demonstrated losses of up to 15.6% within 62 days due to the negative energy balance in experienced soldiers with high levels of physical fitness (US Rangers) 24 . Although we did not assess the physiological or psychological consequences of these reductions in body mass, previous studies have indicated that extreme weight loss during a short-term field exercise can have a significant negative impacts on physical performance (e.g. decreases in power output and strength) 12,32,39 . Maintaining an adequate energy balance during field training and operational missions is paramount to the success of the mission, however, the high energy expenditures experienced during these situations often makes it challenging for military personnel to meet their energy requirements. The present study is strengthened by the use of accurate and precise methods of quantifying both energy intake (measured food intake/waste collection method with precise control over sharing of foods or inclusion of local/supplemental foods) and expenditure (doubly-labelled water). Theoretically, in order to lose the observed weight loss of 2.7% within 5 days (as demonstrated in this study), the participants would have energy deficits of 3150 kcal/day (based on 500 kcal/day to lose 1lb/week). In this study, participants measured energy deficit was 2889 kcal/day, similar to the theoretical value of 3150 kcal/day. Participants’ intakes were less than 50% of the total energy available for consumption from the provided IMPs and LMCs. The low energy intake (2028 kcal) in this study is similar to that found in other cold-environment experiments conducted in CAF personnel, where participants’ energy intakes from field rations have been demonstrated to range from 2475 to 2714 kcal 9,17 . The difference of 400 to 600 kcal (where the energy intake in our study is lower by 400 to 600 kcal) is likely due to several factors. Although, participants in this study were asked to refrain from any personal foods/supplements, other studies conducted in CAF personnel, without such a 120 restriction, have reported the use of supplements, local (e.g. caribou meat) and/or personal foods among soldiers during operational training or deployment 9,17 , which could have contributed to higher energy intakes in those studies. Additionally, the intensity/duration of the activities may also impact intakes differentially between the studies (e.g. in the study by Jones et al., the activity level was reported as moderate 17 ). This study is strengthened by the use of the measured food intake/food waste collection method, which is the current gold standard in dietary assessment methodology 96,181 , whereas previous studies 9,17 used self-reported dietary collection methods (e.g. food diaries) that are prone to misreporting. However, the higher intakes in those studies is consistent with the results of body composition data (but not consistent with assessments of energy intakes) where Jones et al. indicated that the intake of the participants is likely higher than reported (2633 kcal), as participants in that study had minimal loss of weight (0.63kg) 17 , whereas in our study, CAF personnel had a significant reduction in total body mass post-study, consistent with low energy intake, energy deficit and body composition data. Studies conducted in US soldiers on a 10-day exercise in cold weather have also indicated lower energy consumption (2009 kcal to 3553 kcal), even when the personnel were provided with supplemental packs, in comparison to the energy they expended 100 . Although, the average energy content from CAF field rations were sufficient to meet the energy requirements of most participants during the training exercise, the adequate intake of energy by CAF personnel operating or training in the field is dependent upon consumption of the complete ration. Our study was not designed to assess the reasons behind voluntary under-consumption of field ration packs, however, previous research has indicated factors such as menu boredom, poor ration palatability, inadequate time to prepare or eat meals, lack of sleep, and operational stress as contributors to not consuming enough of the rations 2,5 . Previous studies from our group have shown that CAF soldiers generally indicated a good acceptability for the variety of menu item options available as well as the palatability of the rations (Chapter 6, Appendix E) 126 . However, the effect of monotony on field ration acceptability as a result of longer-term consumption of the ration packs needs further consideration. The carbohydrate intake from field rations was within the AMDR. However, most of this carbohydrate was being obtained as simple sugars (total sugar intake 150g), which may be sufficient for sustaining energy for short-term, intense bouts of military exercises, similar to fueling high-intensity athletic performances 137 . Longer-term excess consumption of these simple carbohydrates to sustain prolonged military maneuvers may have health implications 136 . 121 Since military personnel are not consuming their complete ration pack, they are potentially missing out on complex carbohydrates from food items such as rice or couscous found within the field rations. A balanced diet high in complex carbohydrates (these items also contain relatively higher levels of vitamins and minerals) will enhance the nutrient profile of military personnel and benefit them in sustaining energy for both short and long-term missions 137 . Participants’ fibre intake from field rations during the winter weather field training exercise (field rations fibre = 19 g) was lower than the recommended amount (38 g) 80 . Field rations (IMPs) generally have a low content of fresh fruits, vegetables and high fibre foods and provide on average 34 g of fibre. However, supplementation with LMCs, which provide on average 43 g of fibre, and/or personal foods would likely be of benefit in achieving the recommended intake of fibre for CAF military personnel consuming field rations while on operational duties. Although the participants in this study were provided with supplemental LMCs, the overall low energy and nutrient intake in this group of individuals also resulted in less than recommended intake of fibre. Our findings of vitamin A, iron and vitamin C intakes from field rations were comparable to the results from the study by Hatton et al., where the authors also investigated micronutrient intakes in CAF personnel during a cold operational setting 9. Despite partial consumption of rations, participants were obtaining adequate amounts of iron and vitamin C, which is likely a result of high consumption of specific products including vitamin C-fortified drink crystals, which contain high levels of vitamin C, and cereals and peanut butter, which contain high levels of iron. Since it is difficult to obtain appreciable amounts of vitamin A found in fresh foods such as egg yolks, liver, fresh fruits/vegetables during field operations, vitamin A status of CAF military personnel can be improved from fortified sources, such as fruit and energy bars (which are provided within the LMCs) and possibly from personal foods 9. Although intakes from field rations demonstrated calcium intake below the AI value of 1000mg (also the recommended intake as Military DRI), this discrepancy does not necessarily indicate that participants are inadequate in this nutrient 182 . However, considering the strenuous physical and mental demands on military personnel during operational duties and the increased risk for bone-related injuries 22 , ensuring adequate calcium intakes of CAF personnel may warrant further consideration. 122 To our knowledge, this is the first study to explore differences in energy and nutrient intakes from field rations between male and female CAF personnel. Although, we found significant differences in saturated fat, protein, vitamin A and sodium intake between males and females soldiers during the winter weather field training exercise, these effects were eliminated once body mass index and energy intake were taken into account. Our study was not powered to assess the nutrient status of female CAF soldiers, however, studies that have assessed dietary intake differences between male and female soldiers have demonstrated lower nutritional status (e.g. iron or vitamin D) in female personnel during combat training 47,183 . As such, further research is required to assess nutrient requirements of CAF female personnel during prolonged operational and/or training in climatic extremes. Using the FFQ (Canadian Diet History Questionnaire II), participants’ energy intake was estimated to be 1961 kcal prior to the field trial, which is lower than the energy intake of military personnel our research team saw in previous studies (2700 kcal) when measured using a weighed food record. Consistent with previous research which has demonstrated potential energy underreporting with the use of FFQ within specific populations, especially when assessing individual level intakes 103 , our study also showed that FFQs are prone to misreporting where males and females military personnel likely under-reported energy intakes by 32% and 28% (data calculated using estimated energy requirements for highly active Canadians), respectively. These results are similar to a study by Freedman et al., where energy intake reporting bias using FFQ was approximately 30% (range 24%-32%) 184 . The sodium consumption of CAF personnel from field rations and as estimated from the food frequency questionnaire were similar to the Canadian population at large. Given the link between excessive sodium intake and hypertension, a risk factor for cardiovascular disease, the high sodium intakes, even at only 36% of field ration consumption and as estimated in habitual diets, is possibly a cause for concern. As a result, future studies should consider assessing if the habitual diets of military personnel are optimal to ensure operational readiness. In contrast, the high sodium content of field rations is understandable, given the importance of sodium in preservation and the requirement for long shelf lives for IMP without refrigeration. Additionally, military personnel may require additional sodium under situations of sweat losses and strenuous physical activity in temperature extremes 148 . The implications of consuming IMPs for long-term deployments should be considered in future studies. 123 8.6 Conclusions The present study demonstrates the insufficient energy intakes of CAF personnel in relation to energy expenditures, resulting in significant energy deficits during a winter weather field training exercise. As a result, our participants demonstrated voluntary anorexia, as their energy intake was lower than that provided in the form of IMPs and LMCs and their energy intake was insufficient in comparison with their energy expenditure, thereby resulting in significant weight loss. Such results have important implications for impairment of performance and health under longer durations than what was examined in this investigation. Sufficient nutrient intake of CAF military personnel operating in climatic extremes is contingent upon consumption of the complete ration meal 36 . IMPs, if consumed at-least 3 times a day and in their entirety by military personnel conducting strenuous physical activities under climatic extremes, provide sufficient energy and macronutrients. Enhancing the nutrient density of IMPs with LMC supplementation could help with increasing consumption of specific micronutrients with less food. This research indicates the need for development and promotion of strategies to increase the food and nutrient intakes of military personnel during training or operational missions in extreme cold to sustain optimal performance. 8.7 Acknowledgements This study comprised a portion of a larger military feeding project, which was funded by a Defence Research and Development Canada (DRDC) research contract awarded to the University of Toronto. Mavra Ahmed was also supported by a Canadian Institute of Health Research (CIHR) Strategic Collaboration in Public Health Policy Fellowship and an Ontario Graduate Scholarship during her candidature. The authors would like to acknowledge the assistance of the DRDC staff involved in recruiting participants and data collection, the representatives of the Surgeon General of the Canadian Armed Forces co-housed within the DRDC research centre, and the Canadian Forces Environmental Medicine Establishment (CFEME) for provision of experimental medical support. The authors thank the CAF personnel of the DRDC, CFEME, and Dennison Armories, Toronto, Ontario for volunteering to participate in this study. 124 8.8 Author Contributions Ira Jacobs was the principal investigator responsible for the research contract-funding proposal and to whom the funding was awarded that supported this research. Mavra Ahmed, Iva Mandic, Elliot Desilets, Ingrid Smith, Wendy Sullivan-Kwantes and Len Goodman performed the data collection. Mavra Ahmed conducted the statistical analysis of the data and was responsible for drafting the manuscript. Wendy Lou helped with the statistical analysis and interpretation of the data. Wendy Sullivan-Kwantes and Len Goodman were involved in securing the unit and the site for conducting the experimental protocol. All authors were involved in reviewing the manuscript. Mavra Ahmed, Iva Mandic, Len Goodman, Ira Jacobs, and Mary L’Abbe were involved in study conception and design, critical revision of the manuscript, and statistical interpretation. Mary L’Abbe, Ira Jacobs, and Len Goodman were involved in supervision. All authors have reviewed and approved the final manuscript. 8.9 Conflicts of Interest The authors declare no conflict of interest. 8.10 Addressing Links to Next Chapter In this study, we assessed dietary intakes of CAF military personnel using a food intake/food waste measurement technique. However, this technique was challenging to use in the field. These challenges included burden on the participants to keep wrappers of their food items as well as partially consumed or unconsumed food items for collection at the end of the day. Additionally, this required significant time and difficulty for the study coordinator to go through all the food waste and manually weight/input each item. Considering that rations are of known nutrient composition and quantity, using novel mobile techniques such as smartphones that are carried by individuals on a routine basis, might be beneficial in helping to evaluate dietary intakes. As such, the next Chapter will evaluate whether a tablet app (which can also be provided on a smartphone) could be useful in assessing dietary intakes of military personnel. 125 Chapter 9 Validation of a Tablet Application for Assessing Dietary Intakes Compared with the Measured Food Intake/Food Waste Method in Military Personnel Consuming Field Rations This study has been published: Ahmed M, Mandic I, Lou W, Goodman L, Jacobs I and L’Abbé MR. Validation of a tablet application for assessing dietary intakes compared with the measured food intake/food waste method in military personnel consuming field rations. Nutrients. 2017; 9 (3): 200; doi:10.3390/nu9030200. Available from: http://www.mdpi.com/2072-6643/9/3/200 This study addressed objective #5 of my thesis, to: Validate a smartphone application, MyFitnessPal, which was chosen as it allows the addition of nutritional composition data for the field rations, with the current gold standard in dietary assessment methodology: measured food intake with weighed food waste. Student’s contribution: The original idea for this study and its design were mine. I was involved in developing the experimental protocol for this study in collaboration with Iva Mandic, Dr. Len Goodman, Dr. Ira Jacobs and my supervisor, Dr. Mary L’Abbé . I conducted the study (in collaboration with Iva Mandic), collected, entered and analyzed the data. I independently learned the data analysis and reviewed it with Dr. Wendy Lou to ensure my statistical analyses and interpretation of the data were accurate. I independently prepared a draft of the manuscript prior to engaging my co- authors in reviewing and revising the manuscript for subsequent publication in Nutrients. 126 Article Validation of a Tablet Application for Assessing Dietary Intakes Compared with the Measured Food Intake/Food Waste Method in Military Personnel Consuming Field Rations Mavra Ahmed 1, Iva Mandic 2, Wendy Lou 3, Len Goodman 4, Ira Jacobs 2 and Mary R. L’Abbé 1, * 1 Department of Nutritional Sciences, University of Toronto, Toronto, M5S 3E2, Canada; [email protected] (M.A.); [email protected] (M.L.) 2 Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, M5S 2W6, Canada; [email protected] (I.M.); [email protected] (I.J.) 3 Dalla Lana School of Public Health, University of Toronto, Toronto, M5T 3M2, Canada; [email protected] 4 Defence Research and Development Canada – Toronto Research Centre, Toronto, M3K 2C9, Canada; [email protected] * Correspondence: [email protected]; Tel.: +1-416-978-7235 Received: 16 December 2016; Accepted: 23 February 2017; Published: 26 February 2017 9.1 Abstract Abstract: The collection of accurate dietary intakes using traditional dietary assessment methods (e.g. food records) from military personnel is challenging due to the demanding physiological and psychological conditions of training or operations. In addition, these methods are burdensome, time consuming, and prone to measurement errors. Adopting smart- phone/tablet technology could overcome some of these barriers. The objective was to assess the validity of a tablet app, modified to contain detailed nutritional composition data, in comparison to a measured food intake/waste method. A convenience sample of Canadian Armed Forces personnel, randomized to either a tablet app ( n = 9) or a weighed food record 127 (wFR) ( n = 9), recorded the consumption of standard military rations for a total of 8 days. Compared to the gold standard measured food intake/waste method, the difference in mean energy intake was small (−73 kcal/day for tablet app and −108 kcal/day for wFR) ( p > 0.05). Repeated Measures Bland-Altman plots indicated good agreement for both methods (tablet app and wFR) with the measured food intake/waste method. These findings demonstrate that the tablet app, with added nutritional composition data, is comparable to the traditional dietary assessment method (wFR) and performs satisfactorily in relation to the measured food intake/waste method to assess energy, macronutrient, and selected micronutrient intakes in a sample of military personnel. Keywords: dietary assessment; validation; smartphone; technology 9.2 Introduction Dietary assessment methods have traditionally relied on tools such as 24-h recalls, food frequency questionnaires, or multi-day weighed food records (e.g. a 3 Day weighed food record) 108 . Data collection using such methods is prone to measurement errors including recall bias, respondent burden, and the researcher burden of coding recorded foods 109 . Moreover, using manual methods of collection restricts an individual’s ability to understand their food consumption patterns and nutrient intakes and limits the quick and easy analysis of dietary habits at the population level 116,185 . The current gold standard in dietary assessment methodology is the measured food intake/food waste method, wherein the amount of food not consumed is subtracted from the total amount of food given to get a precise measure of the amount consumed 96,181 . Although this method is considered more accurate than other methods that rely on an individual’s memory, the measured food intake/waste method is costly, time consuming, and onerous for both researchers and participants 96,181 . Optimizing the nutritional intake for military personnel is particularly imperative in order to meet the high-energy demands of training and operations 2. Sufficient energy and nutrient intake promotes general health and reduces injury risk 2. Accurately understanding the nutritional requirements to sustain the health and performance of military personnel is integral to ensuring their physiological and psychological wellbeing and operational readiness. 128 Limited data exists about the quantification of energy intake in Canadian Armed Forces (CAF) personnel, who are exposed to extremely challenging training and operations, during which daily energy expenditures can be >6000 kcal/day 11,15,18,126 . Contextualizing the environment in which the participants are reporting energy and nutrient intakes is also imperative in understanding habitual dietary intakes so that the findings can be accurately extrapolated 186 . Precise methods of quantifying dietary intakes are required for both field-based researchers and health professionals (e.g. physicians, dietitians) to provide evidence-based interventions and recommendations on nutritional practices for military personnel under such conditions. However, the collection of accurate and reliable dietary intake data from military personnel is challenging in the field due to physical and cognitive stressors such as ambient temperature extremes, reduced sleep, and heavy load carriage 2,11,31,110 . Considering recent advancements and increases in adopting smart-phone technology, the use of tools such as mobile applications (apps), dietary trackers, and image capturing equipment may overcome some of the barriers associated with traditional dietary assessment methods 109 and be particularly useful for military personnel in the field. Recent reviews have indicated that the use of mobile phone technology in recording dietary intakes is preferred by participants and researchers over traditional methods, while offering the potential to reduce the burden related to coding and analysis 112,185 . There are several commercial mobile apps (e.g. MyFitnessPal and Lose It!) that facilitate the digital recording of dietary intakes 112,113 . Although there are studies testing the effectiveness of some of these apps in promoting health and/or weight-loss 114 , limited data exist on the validation of these commercial mobile apps against the current gold standard of dietary intake methods and/or reference recovery biomarkers to assess their accuracy and reliability in assessing diets 115,116 . Carter et al. (2013) examined the validity of the use of a smartphone app and found that the app correlated with the 24-h recalls, although the limits of agreement were wide for individual energy intakes 187 . This study used a smartphone app designed for weight loss and used 24 h dietary recalls as a reference measure, which is subject to recall bias and misreporting 187 . Additionally, research assessing the use of commercial mobile apps in military personnel, especially CAF, is lacking. Although, McClung et al. (2009) have examined the monitoring of energy intake using a technology-assisted device in a military population, this study used a personal digital assistant, which is rarely used compared to smartphones 110 . 129 Therefore, the present study aims to validate the use of the mobile app MyFitnessPal 127 , which was chosen as it allows the addition of nutritional composition data for the foods provided by the study (in this case military rations or individual meal packs (IMPs)), with the current gold standard in dietary assessment methodology; measured food intake with weighed food waste. The results were also compared with reference recovery biomarker data. 9.3 Materials and Methods 9.3.1 Study Participants This research was conducted at Defence Research and Development Canada (DRDC), Toronto, Ontario between January 2014 and May 2015. The participants were a convenience sample of 18 CAF (mean age 34 years) personnel who were Regular Force or Class A Reservists participating in a concurrent laboratory metabolism and feeding study. A detailed description of the study can be found in the technical report prepared by University of Toronto for DRDC 126 . A total of 27 participants initially volunteered for the study. Two participants never started the protocol, and an additional seven participants dropped out due to scheduling difficulties and/or non-compliance due to the demanding nature of the protocol. All participants provided written informed consent to participate in the study. The Research Ethics Boards at both DRDC (approval code 2013-075) and the University of Toronto (approval code 29914) approved the study. 9.3.2 Demographic and Anthropometric Assessments Participants were asked to complete a questionnaire on demographics. The anthropometric measurements included height, weight, and body fat percentage. Body weight and height were measured without shoes, with light clothing and using standard calibrated equipment (height and weight scales). Body composition (including percent body fat) was assessed using air- displacement plethysmography (BOD POD TM : this is a machine that measures body composition via densitometry). Body mass index (BMI) was calculated as the body weight (kg) divided by the height (m) squared. 9.3.3 Study Procedures Upon written informed consent and completion of the pre-study questionnaires, participants were randomized to either the wFR or the tablet app (full details below). Out of 18 menu items 130 (6 breakfast, 6 lunch, and 6 dinner), participants selected three standard CAF ration packs (IMPs)/day for two consecutive days each week for four weeks. The rations contain pre- packaged pre-labelled food and beverage items (e.g. sliced apples, bread, coffee, breakfast sausages, etc.). Although, participants could only consume the beverages (sports drink, coffee, tea, vanilla cappuccino) provided within the rations, they were able to have water ad libitum. Participants were asked to record their consumption of rations using either the wFR or the tablet app for the duration of the study. All participants were trained in documenting, weighing, and measuring their dietary intake using both methods and were provided with written instructions for reference during the recording period. On the third day, participants were instructed to bring back all food waste from the unconsumed and/or partially consumed ration packs/IMPs, which served as the reference method for the evaluation of each of the two test methods. Study investigators (Mavra Ahmed (MA) and Iva Mandic (IM)) reviewed the food record and/or tablet app details with each participant for each two-day recording period in each of the four weeks. This review involved the clarification of items that may have had missing quantities or may have been misspelled or illegible in the case of the food record. At baseline and at the end of the study, the participants were asked to complete a brief questionnaire on their knowledge, attitude, and behaviour regarding prior or current use of mobile technology and the perceived usefulness and ease of using the tablet app. Response options to the questions included both open ended text as well as Likert-scaled responses on a scale of 1–5. The dietary intakes of participants were derived from food and beverages only for a total of two days each week for four weeks for each method; wFR ( n = 9) and the tablet app ( n = 9). Participants were asked to refrain from the consumption of foods other than the rations. However, in the case where participants were to consume other foods, they were asked to report the intake accordingly. We only had one instance in which a participant had consumed a bowl of salad on one day out of 8 days. We clarified the contents with the participant and ran the analysis with it included. Participants were asked to refrain from vitamin and mineral supplements for the duration of the study. The nutrient values for the combat rations or IMPs were provided by the CAF Directorate of Food Services. For nutrients that were missing (B- vitamins, potassium, magnesium, phosphorus, zinc), values were taken from similar foods in the Canadian Nutrient File 2013 as part of the ESHA© (Elizabeth Stewart Hands and Associates 131 (ESHA©) Food Processor Nutrition Analysis, version 10.13.1, 2013, ESHA Research, Salem, OR, USA) database. Errors made by the participants (e.g. participants may have over- and/or under-reported some items as well as omitting a recording of some items) and outliers were not removed in order to provide an accurate indication of the relative validity of the different dietary assessment methods. Food records (either reported using the wFR or the tablet app) were entered by two trained coders using a nutrient software program (ESHA© Food Processor Nutrition Analysis, version 10.13.1, 2013, ESHA Research, Salem, OR, USA) and double-checked and analyzed by a trained study investigator (MA). 9.3.4 Weighed Food Records (wFR) Participants using the wFR method recorded the time, place, and a detailed description about each consumed food and beverage item. Participants were provided with household measuring utensils and a standard food scale (PrepTech, PT-800, Newport Beach, CA, USA) to weigh each food item. 9.3.5 Tablet App Participants using the tablet app, MyFitnessPal, were provided with a Samsung ® Galaxy Tab 3/Note 3 with the app pre-downloaded. The app, MyFitnessPal, had a full list of CAF rations/IMPs nutritional information added to the database by a study investigator (MA). Participants were able to search for their food/beverage item of choice and add it to the respective meal; breakfast, lunch, dinner, and/or snacks. All items within the combat rations/IMPs were packaged in pre-determined quantities. Participants were provided with household measuring utensils and a standard food scale (PrepTech, PT-800, Newport Beach, CA, USA) to weigh each food item. 9.3.6 Measured Food Intake/Weighed Food Waste Method (Reference Method) Participants selected three ration packs per day and were asked to bring back all unconsumed and/or partially consumed food and beverage items. The study investigators (MA and IM) weighed and recorded all the partially consumed food and beverage items to the nearest gram or 132 millilitre, using a standard food scale (PrepTech, PT-800, Newport Beach, CA, USA). The measured food intake/food waste was calculated from the amount unconsumed subtracted from the known quantity of each menu item selected and brought home. 9.3.7 Urinary and Blood Biomarkers Participants were instructed to collect their urine for 24 h immediately before coming back to DRDC for fasting blood collection on Day 3 of each week. Participants were provided with a plastic container to collect their urine and a leak-proof bag in which to store their urine container. Participants were instructed to discard the first urine sample of the day and to collect all subsequent urine for the next 24 h, including the first urine sample on the following day. Venous blood samples (10 mL) were collected from each participant after an overnight fast. Erythrocytes and plasma were separated within 1 h of collection. Both the urine and plasma samples were shipped to a third party blood chemistry laboratory (Lifelabs, Toronto, ON, Canada) for processing. Creatinine excretion was used to assess the adequacy of the urine collections by using creatinine excretion standards (<8.8 mmol/day for males and <4.5 mmol/day for females) 156 . 9.3.8 Statistical Analyses All data are presented as mean ± Standard Deviations (SD). Multiple regression for repeated measurements was used to examine the relationship between the nutrient intake data estimated using the tablet app or wFR (dependent variables) and the measured food intake/waste method (predictor variable), adjusted for multiple days 188 . The Repeated Measures Linear Mixed Model was used to test for differences in the data collected using the tablet app or the wFR and the measured food intake/waste method, adjusted for 8 days of recording and collection per method. A Repeated Measures Bland-Altman 189,190 analysis was used to assess the relative bias (mean difference) and random error (1.96 Standard Deviation (SD) of the difference) between the tablet app or the wFR with the measured food intake/waste method. Correlations for association between dietary intakes (averaged for two consecutive days over four weeks) (dependent variable) and urinary/blood biomarkers (four collections per participant) (predictor variables) with adjustments for age, energy intake, and body mass index as possible covariates were 133 obtained using multiple regression 188 . All data were analysed using SPSS Statistics (version 24, 2016; IBM Corporation ®, Armonk:NY, USA), and statistical significance was set at p ≤ 0.05. 9.4 Results 9.4.1 Participant Demographics and Anthropometrics The participants’ demographics and anthropometric measurements are summarized in Table 1. Of the 18 CAF participants who participated in the study, 78% were male and 67% were Caucasians. The mean age of participants was 34 ± 11 years, with a mean BMI of 26 ± 3.6 kg/m 2 and a mean percent body fat of 23% ± 8.1%. The majority of the participants had a university degree (61%). Table 1. Characteristics (demographics and anthropometrics) of the study participants. Characteristics n = 18 Age (year) 1 34 ± 11 Sex 2 Male 14 (78%) Female 4 (22%) Height (cm) 1 174 + 10 Weight (kg) 1 79 + 13 Body Mass Index (kg/m 2) 1 26 ± 3.6 Percent Body Fat (%) 1 23 ± 8.1 Ethnicity 2 Caucasian 12 (67%) Asian 3 (17%) African American 1 (6%) Hispanic 1 (6%) Other 1 (6%) High-school graduation 1 (6%) Non-university certificate 6 (33%) University Degree 11 (61%) Marital Status 2 Single 12 (67%) Married 5 (28%) Separated 1 (6%) 1 Mean ± Standard Deviations (SD). 2 n (%). 134 9.4.2 Smartphone and Tablet Usage A vast majority (89%) of our participants used a smartphone as their primary phone on a daily basis, and 67% used it to keep track of their physical activity and dietary habits. Of the tablet users (n = 9), 89% of users found the tablet app easy to use, 67% found it comfortable to carry around, and 56% thought the app helped them to record their food items accurately. 9.4.3 Comparison of Tablet App with Measured Food Intake/Food Waste Method There were highly significant correlations between the tablet app and the measured food intake/waste method for both macro- and micro-nutrients (correlations ranging from 0.963 to 0.999; p ≤ 0.05) (Table 2). The differences between the methods were not significantly different (p > 0.05) for nutrients energy, carbohydrates, fat, saturated fat, protein, vitamin A, vitamin C, calcium, iron, and sodium. For all of these nutrients, the tablet app yielded lower intakes than the measured food intake/waste method; with intakes approximately 3% lower for energy and carbohydrates, 4% lower for fat, 2% lower for protein, and 3%–12% lower for micronutrients. For energy intake, the mean difference between the tablet app and the measured food intake/waste method was not significant (−73 kcal/day; 95% Confidence Interval (CI) for bias = −109 to −37 kcal/day) ( p > 0.05). Although the tablet app had a 3% bias towards under- reporting energy intake in comparison to the measured food intake/ waste method, the 95% CI for this bias was narrow (−1.5% to −4.5%). For random error, the 95% lower and upper Limits Of Agreement (LOA) between the methods for energy intake ranged from −250 to 104 kcal/day. Similarly, the mean difference for carbohydrate (−12 g/day), fat (−2.21 g/day) and protein intakes (−1.25 g/day) was not significant ( p > 0.05), with a narrow 95% LOA (−43 to 19 g/day for carbohydrates, −9 and 4.5 g/day for fat and −5.5 to 3 g/day for protein). Similar results were found for other nutrients (Table 2). The Bland-Altman plots (Figure 1) for energy, macronutrient, and micronutrient intakes demonstrate that data for most participants were within the LOA with few outliers. There was no apparent proportional bias, suggesting that the differences between the two methods occurred at random across the range of intakes. 135 Table 2. Daily energy and nutrient intakes recorded by Canadian Armed Forces (CAF) personnel participants using the tablet app 1 (n = 9) compared to the measured food intake/food waste method 2 (reference method) (Means ± Standard Deviations (SD)). Nutrients † Tablet App 1 Measured Food Correlation Difference Limits of p-Value ** n = 9 Intake/Waste Method 2 Coefficient ( r) Agreement (LOA) § Mean (SD) Mean (SD) Mean (SD) Lower Upper Energy (kcal/day) 2410 (651) 2484 (670) 0.992 * −73 (89) −250 104 0.42 Carbohydrates (g/day) 359 (110) 371 (113) 0.992 * −12 (16) −43 18 0.47 Fat (g/day) 68 (29) 71 (29) 0.993 * −2 (3.4) −9 4.5 0.46 Saturated Fat (g/day) 24 (11) 25 (11) 0.993 * −0.8 (1) −3.4 1.8 0.53 Protein (g/day) 87 (23) 89 (23) 0.996 * −1.3 (2) −5.5 3 0.71 Vitamin A (μg/day) 7 (41) 8 (41) 0.999 * −0.3 (1.5) −3.4 2.7 0.96 Vitamin C (mg/day) 200 (160) 211 (160) 0.985 * −11 (28) −67 45 0.66 Calcium (mg/day) 513 (223) 532 (220) 0.989 * −19 (35) −88 50 0.49 Iron (mg/day) 18 (6) 19 (6) 0.994 * −0.4 (0.7) −2 1 0.64 Sodium (mg/day) 3725 (1061) 3835 (1083) 0.963 * −109 (292) −684 465 0.44 * p ≤ 0.05; ** p-value is the significance level for differences between two methods. § Lower and upper Limits Of Agreement (LOA) (mean difference ± 1.96 SD). † Energy and nutrient intake data examined by Multiple Regression and differences estimated by Repeated Measures Linear Mixed Models. 1 Tablet App; tablet was preloaded with MyFitnessPal app software, which was modified to contain nutritional composition of all possible military ration choices. 2 Measured Food Intake/Waste Method; all consumed and/or non-/partially consumed food and beverage items from the military ration packs were weighed and recorded for each participant. Figure 1. Repeated Measures Bland-Altman plots of the difference between intakes recorded by the tablet app and those from the measured food intake/food waste method against the mean values for the two methods for ( a) energy; ( b) carbohydrates; ( c) fat; and ( d) protein. The solid line indicates the mean difference (energy −73 kcal/day, carbohydrates −12 g/day, fat −2.21 g/day and protein −1.25 g/day), and the dashed line indicates the 95% Limits Of Agreement (LOA) (1.96 SD) for nutrient intakes (energy −250 kcal/day, 104 kcal; carbohydrates −43 g/day, 18 g/day; fat −8.91 g/day, 4.5 g/day and protein −5.52 g/day, 3.03 g/day). 136 9.4.4 Comparison of Weighed Food Record (wFR) with Measured Food Intake/Waste Method There were highly significant correlations between the wFR and the measured dietary intake for both macro- and micro-nutrients (correlations ranging from 0.904 to 0.996, p < 0.001), and there were no differences between nutrients ( p ≥ 0.05) (Table 3). For all of the nutrients, the participants reported lower intakes using the wFR than that obtained from the measured dietary intake, with intakes approximately 3.5% lower for energy and fat, 4% lower for carbohydrates, 2% lower for protein, and 0% to 19% lower for micronutrients (Table 3). For energy intake, the mean difference between the wFR and the measured dietary intake was small (−108 kcal/day, p ≥ 0.05), with a 95% lower and upper LOA of −338 to 122 kcal/day, respectively. Similar to the tablet app, the wFR method had a 3.5% bias towards underreporting, although the 95% CI for bias was narrow (5% to 2%). The mean differences for carbohydrate (−19 g/day), fat (−3 g/day), and protein (−1.8 g/day) intakes were small ( p > 0.05) with a narrow 95% LOA (−58 to 19 g/day for carbohydrates, −11 and 5 g/day for fat and −8 to 4 g/day for protein). Similar results were found for other nutrients, where no mean difference ( p > 0.05) and a narrow 95% LOA between the methods (Table 3) was seen. The Bland-Altman plots (Figure 2) for energy and macronutrient intakes demonstrate that most participants fell within the LOA with few outliers in the data. There was also no apparent proportional bias, suggesting that the differences between the two methods occurred at random across the range of intakes. 137 Table 3. Daily energy and nutrient intakes recorded by CAF personnel using the weighed food record (wFR) 1 and those obtained from the measured food intake/food waste method 2 (reference method) (Means ± Standard Deviations (SD)). Nutrients † Weighed Measured Food Correlation Difference Limits of Agreement p-Value ** Food Record 1 Intake/Waste Coefficient ( r) (LOA) § n = 9 Method 2 Mean (SD) Mean (SD) Mean (SD) Lower Upper Energy (kcal/day) 2972 (900) 3080 (902) 0.993 * −108 (117) −338 122 0.32 Carbohydrates 449 (145) 469 (146) 0.993 * −19 (20) −58 19 0.30 (g/day) Fat(g/day) 87 (30) 90 (30) 0.992 * −3.1 (4) −11 5 0.38 Saturated Fat 32 (11) 33 (12) 0.993 * −0.96 (1.4) −4 2 0.51 (g/day) Protein (g/day) 101 (31) 103 (30) 0.996 * −1.8 (3) −8 4.2 0.65 Vitamin A (μg/day) 7 (8) 9 (8) 0.904 * −1.8 (3.7) −9.1 5.5 0.09 Vitamin C (mg/day) 300 (201) 307 (201) 0.994 * −6.7 (23) −52 39 0.80 Calcium (mg/day) 619 (297) 655 (297) 0.984 * −36 (59) −152 79 0.37 Iron (mg/day) 22 (9) 22 (9) 0.995 * −0.6 (0.96) −2.5 1.3 0.60 Sodium (mg/day) 4640 (1228) 4759 (1256) 0.987 * −119 (212) −535 297 0.48 * p ≤ 0.05; ** p-value is the significance level for differences between two methods. § Lower and upper limits of agreement (LOA) (mean difference ± 1.96 SD). † Energy and nutrient intake data examined by Multiple Regression and differences estimated by Repeated Measures Linear Mixed Models. 1 Weighed Food Record (wFR); participants using the wFR method were asked to weigh and record each consumed food and beverage item on a paper-based self-report form. 2 Measured Food Intake/Waste Method; all consumed and/or non-/partially consumed food and beverage items from the military ration packs were weighed and recorded for each participant. Figure 2. Repeated Measures Bland-Altman plots of the difference between intakes recorded by the wFR and those obtained from the measured food intake/waste method against the mean values for the two methods for (a) energy; ( b) carbohydrates; ( c) fat; and ( d) protein. The solid line indicates the mean difference (energy −108 kcal/day, carbohydrates −19 g/day, fat −3.1 g/day and protein −1.8 g/day) and the 138 dashed line indicates 95% LOA (1.96 SD) for nutrient intakes (energy −338 kcal/day, 122 kcal; carbohydrates −58 g/day, 19 g/day; fat −11 g/day, 5 g/day, and protein −8 g/day, 4.2 g/day). 9.4.5 Relationship between Dietary Assessment Methods and Biomarkers of Intake The data showed moderate to good correlations where the urinary urea:creatinine ratio (unadjusted, r = 0.34; adjusted r = 0.91) and the plasma ascorbic acid (unadjusted, r = 0.35; adjusted r = 0.56) were significantly related to dietary intakes using the tablet app ( p ≤ 0.05) (Figure 3a,c) after the adjusted values were controlled for age, energy intake, and body mass index. For the relationship between dietary intakes reported using the wFR and the biomarkers of intake, urinary urea:creatinine ratio (unadjusted, r = 0.21; adjusted r = 0.90) was significantly related to protein intake ( p ≤ 0.05) after adjustment. Without adjustment, ascorbic acid was not significantly related to vitamin C intake ( r = 0.2; p > 0.05), but when controlled for age, body mass index, and energy intake, the correlation coefficient between vitamin C intake and plasma ascorbic acid was significantly positively correlated ( r = 0.72, p ≤ 0.05) (Figure 3b,d). 139 Figure 3. Scatter plots of the relationship between ( a,b) urinary urea:creatinine ratio and dietary protein intake and between ( c,d) plasma ascorbic acid and dietary vitamin C intake recorded by the ( a,c) tablet app and by ( b,d) wFR. The correlations are examined using multiple regression for repeated measurements and presented unadjusted. Data presented is for dietary intake (two days averaged per week for four weeks = four days) and urinary and blood biomarkers (four collections) per participant. The four sets of colors represent individual participants. 9.5 Discussion The present study demonstrated that a tablet app with integrated military ration nutritional information data is comparable to the traditional wFR method to assess dietary intakes in military personnel under non-operational settings. Our study showed that the participants preferred to use the tablet app to keep track of their dietary intake (in contrast to the food record when they had the opportunity to try both methods prior to the study), which was in agreement with Jospe et al. 116 , who found a positive perception of diet app usage by dietitians to assess or track intakes. In addition, Lieffers et al. 191 also indicated that diet apps were convenient and easy to use for keeping track of dietary intake. 140 This study demonstrated good correlations between using the tablet app with the measured food intake/waste method for total energy, macronutrient, and micronutrient intakes. These correlations compared favourably with results from other validation studies of technology- assisted dietary assessment methodologies 110,112,187,192,193 . Carter et al. 187 compared a smartphone app with 24-h recalls and found correlations ranging from 0.63 to 0.83, which are quite a bit lower than those seen in our study. Our findings of high correlations between the tablet app and the measured food intake/waste method are likely due to the use of standardized pre-weighed rations with known nutrition information. Similarly, our findings demonstrated good correlations between the wFR and the measured food intake/waste method, indicating that measurement of nutrient intake levels using the tablet app is comparable to that from the wFR; which is currently considered a robust method of assessing diets when information on multiple days of dietary intake has been recorded 103 . The Bland-Altman plots indicated a good level of agreement between each method (tablet app or wFR) and the measured food intake/waste method at a range of intakes, with most of the data points located within the 1.96 SD of the mean (narrow LOA). This indicates that the tablet app is suitable for accurately estimating intakes at an individual level. Our finding of narrow LOA is consistent with the results by Timon et al. 192 but in contrast to studies comparing either a smartphone app or a Personal Digital Assistant (PDA) with 24-h recall 112,118,187 . As suggested by the authors of these latter studies, this could be possibly due to measurement errors found in the reference measure (24-h recall), which itself is not a measure of absolute intakes as it is not representative of habitual/usual intakes and is prone to recall bias and misreporting 187 , whereas we were able to measure absolute food intake with our use of the current gold standard (measured food intake/food waste method). Although the study showed relatively good agreement between the two methods, as illustrated by the Bland-Altman analysis, there were lower mean daily dietary intakes reported by the tablet app than by the measured food intake/waste method (although these were not significantly different), reflecting some measure of systematic bias. Similar results were found for the agreement between the wFR and the measured food intake/waste method. However, it should be noted that the participants in this study were consuming standardized military rations with low variability in their nutrient compositions, and the variety of food items from which the choices were made was quite narrow, therefore further reducing variation between participants and the 141 potential to underreport. In light of the relatively narrow variety in menu items available in rations, we used the repeated measures linear mixed model approach, which utilizes the repeated measurements on each individual while accounting for variation within participants. Additionally, the magnitude of the bias in energy intakes from both the tablet app (−73 kcal/day) and the wFR (−108 kcal/day) were small with a narrow 95% CI for bias. Our findings of underreporting in both the methods are lower than the energy intake of 110 to 165 kcal/day, which is considered to be clinically meaningful for weight loss 186,194. This suggests that the under-reporting seen in this study will not likely impact energy balance in this sample of CAF personnel and that the tablet app could be a valuable tool for self-reporting dietary intakes in a sample of military personnel under non-operational conditions. Although limited studies exist in quantifying the accuracy of energy intakes within military personnel using mobile phone technology, our findings of underreporting of 3% and 3.5% are lower than those seen in national population-based surveys, in which the underreporting of energy intake has been estimated to range from 10%–20% 195,196 . The low rate of underreporting in our study is also an improvement in comparison to some studies, using the food record and/or 24-h recalls as a reference method, that underestimate energy intake by 6% or more 123,197,198 . Similar to our findings, some studies using training/reminders, weighed meals, and/or total energy expenditure as a reference method in evaluating or validating digital-assisted dietary assessment methods have found underreporting ranging from 3%–4% 110,199 . Participants in our study were shown and given written instructions on how to weigh and measure food quantities and how to use both the wFR and the tablet app methods to record dietary intakes. Additionally, military personnel have been shown to display traits of higher inherent motivation levels, especially when it comes to enhancing performance and maintaining weight 200 . All of these factors may have contributed to improved compliance among our participants, which may explain the low bias and good agreement demonstrated in this study. Thus, the small underreporting is likely a true reflection of a systematic bias of 3%–4% using these methods (tablet app or wFR). There are several possible reasons for the finding of small under-reporting from the tablet app evident in this study; the most important being that participants were able to see the feedback display of nutrient intakes on the app 115 , which may have resulted in an unintended behavioural change. Alternatively, participants may have failed to enter all of the food items and may not 142 have provided accurate assessments of food portion sizes 187,192,193,201 , although the latter is unlikely because the ration packages are all pre-weighed and participants were provided with food scales and measuring cups/spoons to weigh the leftovers. Finally, the small underreporting seen in both the tablet app and wFR is possibly due to the burden upon respondents to record detailed dietary information by pen/pencil or by typing 185 . Reference biomarkers of dietary intake provide an objective method to validate selected components of dietary intakes 192,202 . Using multiple regression and after adjusting for covariates, we found a positive significant correlation between the dietary intakes from both the wFR and the tablet app with the biomarkers. Our findings are similar with the results found in another study validating technology-assisted dietary assessment methods with biomarkers 192 . Some of the lack of association for the unadjusted correlation is probably due to our small sample size, differential misreporting, or covariates such as energy intake, BMI, and age, which, when added to the data, improved the correlations. We also noticed that individuals using the tablet app recorded a 5% lower intake of sports drinks (which contain high amounts of vitamin C) in contrast to participants using the wFR, which may explain the lower association between the reported vitamin C intake using the tablet app and plasma ascorbic acid. One of the main strengths of our study is the validation of a tablet app in assessing dietary intakes in a sample of military personnel consuming food/beverages of known nutritional composition with the food waste method, the current gold standard in assessing diets 103,203 and biomarkers in a real world setting (at home over a period of 8 days). However, it is important to acknowledge that the majority of the participants in our study were highly compliant and appeared to be comfortable with the use of technologies; therefore, the results of our study may not be generalizable to the general healthy Canadian adult population. In addition, our study investigators conducted one- on-one training for each participant to ensure accurate recording of dietary intake, which may not be feasible for larger studies. 9.6 Conclusions Current findings suggest that a tablet app, when modified to contain detailed nutritional composition data, is comparable to the traditional method of assessing dietary intakes (wFR). The tablet app also performed satisfactorily compared to the measured food intake/food waste method (current gold standard) and could offer a mobile alternative to the wFR for the estimation of dietary intake in a sample of CAF personnel under operational conditions. 143 Although promising as an alternate dietary assessment method for monitoring the dietary intake of military personnel, the tablet app still needs to be validated in a larger sample size and under military operational settings of added physical and psychological stress. 9.7 Acknowledgements This study comprised a portion of a larger military feeding project, which was funded by a Defence Research and Development Canada research contract awarded to the University of Toronto. Mavra Ahmed was also supported by a Canadian Institute of Health Research (CIHR) Strategic Collaboration in Public Health Policy Fellowship and an Ontario Graduate Scholarship during her candidature. The authors would like to acknowledge the assistance of the DRDC staff involved in recruiting participants and data collection the representatives of the Surgeon General of the Canadian Armed Forces co-housed within the DRDC research centre, and the Canadian Forces Environmental Medicine Establishment (CFEME) for provision of experimental medical support. The authors thank the CAF personnel of the DRDC, CFEME, and Dennison Armories, Toronto, Ontario for volunteering to participate in this study. 9.8 Author Contributions Mavra Ahmed, Iva Mandic, and Len Goodman performed the data collection. Mavra Ahmed conducted the statistical analysis of the data presented and was responsible for the draft of the manuscript. Wendy Lou helped with the statistical analysis and interpretation of the data. Mavra Ahmed, Iva Mandic, Len Goodman, Ira Jacobs, and Mary L’Abbe were involved in study conception and design, critical revision of the manuscript, and statistical interpretation. Mary L’Abbe, Ira Jacobs, and Len Goodman were involved in supervision. All authors have reviewed and approved the final manuscript. 9.9 Conflicts of interest The authors declare no conflict of interest. © 2017 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). 144 Chapter 10 Overall Discussion At the outset of this thesis research, there were no data on the habitual at home dietary intakes of CAF personnel and dated/limited research on the nutritional assessments and requirements of CAF military personnel in extreme environmental temperatures. As a result, this thesis assessed the nutritional status of a convenience sample of CAF military personnel with the overarching objective of generating data related to better understanding the nutritional requirements in relation to energy deficits of military personnel on field rations during training and/or field operations. The results of this thesis produced five key findings. First, it was shown that energy intake was not reduced due to palatability of rations in an acute setting and second, that this sample of CAF personnel had less than recommended intakes of specific micronutrients both from their habitual diets at home and when consuming ad libitum field rations under thermally neutral conditions. Third, we found that, even with the challenge of increased energy expenditure and temperature stress in the experimental study conducted in the environmental chamber, CAF military personnel’s energy consumption from field rations in extreme environmental temperatures and with strenuous physical activity was similar to their energy consumed under thermally neutral sedentary condition (i.e. participants did not consume more energy in situations of higher energy expenditures even when they had ample time to eat and rations were provided for them on demand). Fourth, we assessed the added challenge of limited time to prepare and consume field rations under extreme winter weather environmental stress in a real-life training scenario and found that CAF reservists demonstrated insufficient energy intakes relative to the energy expended which contributed to a significant weight loss over the 5-day training course. And finally, considering the challenge of using traditional dietary assessment methodologies for assessing dietary intakes under field conditions, the fourth study demonstrated the potential to use mobile technology (e.g. a smartphone app or tablet) to better monitor and understand nutrient intakes of CAF military personnel. Additional results from this thesis have also explored three areas of potential concern in planning nutrition programs and interventions for optimal mental and physical performance of actively deployed military personnel. First, this thesis has demonstrated high sodium intakes in 145 a convenience sample of CAF military personnel even when field rations were only partially consumed. Second, we found that the stress of environmental temperature is likely to impact acute concentrations of urinary biomarkers (e.g. sodium). And finally, we explored the differential nutrient intakes (especially micronutrients) of male and female CAF personnel. The following sections will discuss both the key and sub-findings in detail and examine their implications. 10.1 Insufficient Energy Intake in Relation to Energy Requirements In Chapter 6, we demonstrated the acceptable energy intake of CAF military personnel in relation to energy requirements for active individuals under conditions of routine or usual activities in thermo-neutral environments. These results are contrary to that of the healthy Canadian adult population, where the majority of the Canadians are exceeding their energy intake requirements 131 relative to energy expended. Our findings are unique and have implications for ensuring that CAF military personnel continue to consume acceptable amounts of energy relative to their metabolic requirements as active or highly active individuals. Although, our study in Chapter 6 was not designed to assess the top sources of foods where most of the energy were being obtained, novel findings from our recent abstract (Appendix C) shows that CAF personnel were consuming higher amounts of meat and alternatives and were obtaining 30% of total energy from ‘other foods’ with lower intakes from fruits and vegetables, illustrating the lower diet quality of our sample of CAF personnel. These have implications for ensuring that CAF personnel may require improvements for optimal diet quality. Under thermo-neutral and comfortable conditions, we found energy intake from 70% consumption of field rations to be comparable to that from their habitual dietary intakes. These findings demonstrate that participants’ short-term energy intake is not dependent upon the palatability of the field rations and as such, CAF military personnel consumed energy amounts similar to their at home energy amounts. This finding is also strengthened by the surveys we conducted on the acceptability of field rations among our participants (Appendix E), where the data showed that the majority of participants’ ranked the field rations as acceptable in menu item variety and palatability. During the ad libitum consumption of field rations at home, participants had time to eat and prepare the rations without the added stress of environmental 146 temperature extremes and strenuous physical activities, yet did not consume the entire ration pack. Factors contributing to participants’ incomplete consumption of the entire ration pack during at home conditions may include (but not limited to): a) their intake relative to their requirements (less in comparison with training or operating under harsh environmental temperatures) under at home conditions or b) participant avoidance of certain ration components. However, considering that field rations are typically provided during field operations where the energy expenditures of military personnel are higher than usual activities and may be provided for a longer time period than examined in this study, solider avoidance of certain ration components or ration monotony can increase the risk of insufficient intake. Data from our field study (Chapter 8) indicated that participants generally consumed food items that were easy to carry and consume while on the move (e.g. chocolate/energy bars, sachets of sports drinks, bread), while items that require preparation or utensils were generally discarded (e.g. some main entrees, dessert items). This pattern of food consumption is similar to that found in a study by Goodman et al., where time penalty and challenges associated with handling/preparing rations in the cold environment resulted in consumption of items that were easy to consume ‘on the go’ 75 . Condiments were also not consumed during the field training exercise. As a result, consideration of items typically avoided by participants should be further studied, especially during field operations. In Chapter 7, we assessed energy intake under the added stress of temperature extremes and demanding physical activities. The novel findings from this study demonstrated that, even with the challenge of environmental stress and simulated military-type strenuous activities (but having ample time to eat and provision of ad libitum field rations that were readily available/prepared on request), there were no differences in energy intakes between the temperature extremes in comparison with the sedentary condition in a temperate environment. Measured food intake data indicated that participants’ energy intake was less then their energy expenditure during the 8-hour treatments in the harsh environmental temperatures with strenuous physical activity. During the subsequent 16-hour (at home post-treatments), participants did not compensate for this increased energy expenditure by increasing energy intake once the stress of physical activity and temperature had subsided. As such, participants are likely consuming insufficient amounts of energy in relation to the energy they are expending and these results have implications for a higher risk of insufficient energy intake if the study were to be conducted for a longer time period then what was examined. 147 In Chapter 8, we examined additional challenges that may potentially impact intakes from field rations in a real-world training situation, for example: 1) limited time to eat and prepare the food; 2) potential sleep impairments and; 3) relatively longer-term demanding activities in extremely cold condition. The results showed that participants consumed 36% of the total energy provided in the field rations (combined IMPs and LMCs) and 41% of the energy expended, resulting in a 2.7% significant loss of body mass in 5 days. These findings demonstrate that participants exhibited voluntary anorexia, and thus, this may have potential impacts on impairments in performance and health of military personnel if they are exposed to 204 such conditions on a longer-term basis (e.g. during field missions) . This study is strengthened with the use of best available methods of dietary assessments (measured food intake/waste collection method) coupled with the best available and gold standards in energy expenditure measurements (doubly-labelled water), thereby demonstrating precise quantification of the energy deficits, contributing to voluntary anorexia during a short- term exercise training program in a cold environment. 10.2 Optimizing Consumption of Macronutrients and Fibre Although it is well established that adequate nutrient intakes during military operations are important for physical and mental performance; dietary choices and behaviours, including the preference for foods consumed on a routine or usual basis, can impact overall physiological/psychological performance, sleep and health 27 . Optimizing both pre- and during- deployment consumption of food may aid in better nutrition for military personnel, thus contributing to their operational readiness 18 . In Chapter 6, we demonstrated that participants’ total energy and macronutrient intakes were similar from habitual diets and from ad libitum consumption of field rations, and were found to be within the DRI recommendations (AMDR). However, anecdotal reports and assessments of habitual diets revealed participants’ preference for higher protein in comparison to carbohydrates, which are the major source of fuel obtained from field rations. Current recommendations do not suggest increases in protein requirements, beyond what is supplied in field rations, for military personnel 3. However, research has indicated deficits in whole-body protein turnover as a result of winter military training while consuming field rations 34 and potential beneficial effects of protein on muscle endurance, recovery and mitigating 148 psychological stress 205 , which may indicate several potential advantages of greater protein intake. Considering the relatively high protein intake during their habitual diets, the extent to which a lower protein intake (as a result of partial consumption of field rations) could contribute to impaired recovery and endurance during operating or training in harsh climates for CAF personnel is unknown and should be further assessed in future studies. Field rations generally provide a higher amount of carbohydrates relative to fat and protein, which is beneficial during field operations as carbohydrates are considered the major source of energy to fuel strenuous physical activity. In Chapter 6 and 8, we demonstrated that most of the carbohydrates found in field rations was being obtained as simple sugars, which may be sufficient for sustaining short-term, intense bouts of military exercises 137 but longer-term excess consumption of simple carbohydrates to sustain prolonged military maneuvers may not be ideal 136 . Since military personnel are not consuming their complete ration pack, they are potentially missing out on complex carbohydrates from food items such as rice or couscous found within the field rations. A balanced diet high in complex carbohydrates (these items also contain relatively higher levels of vitamins and minerals) will enhance the nutrient profile of military personnel and benefit them in sustaining energy for both short and long-term missions 137 . As such, further research is warranted on sugar assessments and optimal proportions of different types of carbohydrates for CAF personnel operating in environmental extremes. In Chapter 7, we did not see a difference in macronutrient preference or intake across different conditions, however, our results demonstrated that the field rations provided sufficient amounts of macronutrients if military personnel were to consume the rations in their entirety and eat at- least 3 meals per day. As such, strategies to optimize complete consumption of field rations or higher nutritional dense foods should be explored. Whether CAF military personnel require differential ratios of carbohydrates, fat and protein under extreme environmental conditions are still unknown. CAF military personnel were obtaining lower than recommended amounts of fibre from their home diets and from ad libitum consumption of field rations as demonstrated in Chapter 6. Additionally, both Chapter 7 and 8 demonstrated that fibre intake was lower than recommendations of 38g in the experimental trial and during the winter weather field training exercise, as a result of partial consumption of rations as well as the rations themselves providing slightly lower than recommended amounts of fibre. Considering that field rations 149 have a low content of fresh fruits/vegetables and high fibre foods, it is difficult to obtain the recommended amount of fibre from IMPs alone, especially since military personnel are not consuming the ration pack in its entirety. Supplementing with LMCs (which contains additional fibre) during operations in temperature extremes may be beneficial for obtaining sufficient fibre intakes. However, considering variable effects of field rations on bowel movements in CAF military personnel during military operations 141 , whether higher than recommended amounts of fibre could potentially interfere with tactical mobility should be further explored. In summary, although IMPs, if consumed in their entirety, appear sufficient to provide adequate energy and macronutrients for military personnel, ensuring adequate provision and consumption of food/beverages in harsh operational environments should remain an operational priority. 10.3 Less than Recommended Intakes of Micronutrients Data on micronutrient intakes of CAF personnel from habitual diets was lacking. Additionally, there was limited and dated research assessing micronutrient status of military personnel while operating under environmental stress. The results in Chapter 6 demonstrated that a sample of CAF personnel had less than recommended intakes of micronutrients in comparison to the MDRI recommendations (although a greater proportion were meeting the DRI (EAR) recommendations), both from habitual diets and from ad libitum consumption of field rations. These findings are comparable to the micronutrient intakes of the healthy Canadian adult population, where the prevalence of inadequacy for the above micronutrients range from 40% to 87% 131 . Although, our results may not be representative of all CAF personnel, they do highlight the importance of better understanding the nutrient status, specifically micronutrients, of CAF military personnel consuming their ‘usual’ diets at home. These novel findings may have implications for optimizing nutrient status of soldiers pre-deployment in order to ensure operational readiness. Importantly, as illustrated in Chapter 7 and 8, the rations were not consumed in their entirety, thus, further contributing to less than recommended intakes of micronutrients. Although meeting the complete MDRI/DRI recommendation for micronutrients is dependent upon the selected menu ration combinations and the amount consumed, this novel finding may have 150 implications for impacting health and performance of military personnel, if low intakes were to extend to periods longer than those investigated. These results, however, should be interpreted with caution because they are based on individual assessments of nutrient intakes with statistical approaches that may not be reliable estimates of intakes from field rations or from habitual diets of military personnel. The field rations and its components were consumed episodically for limited number of days, which does not adequately capture the ‘usual’ intakes from field rations under operational conditions (which would require studies with a larger sample size and more days of intake data). In Chapter 7, we demonstrated that the intake of micronutrients could potentially differ under environmental extremes, partially as a result of the consumption of specific food items. For example, vitamin C content is mostly found in vitamin-C fortified drink crystals and the intake was found to be highest in hot and temperate conditions relative to the cold condition, likely as a result of consuming higher amounts of the drink crystals. As such, participants are likely to have lower than optimal intakes of vitamin C under cold environments. Similarly, our findings of low intake of magnesium in the simulated cold condition relative to the hot condition is likely to have implications for hindering work capacity during cold stress 19,45,206 . This indicates that soldiers may differentially consume specific food items during military operations, where preferences may be contingent upon a combination of the temperature extreme or physical activity. In Chapter 8, we demonstrated that soldiers consumed low amounts of micronutrients as a result of partial consumption of field rations during the winter weather field training exercise. Specifically, the low intake of vitamin A and calcium (which were also found to be low in Chapter 6 and 7) may have implications for bone-related injuries and suboptimal performance 22,47 if the rations are to be consumed in partial amounts and for longer periods of time than investigated in this study. As such, enhancing the nutrient density of IMPs with LMCs or with personal foods can help with increasing the consumption of specific micronutrients under situations where soldiers are consuming partial IMPs while conducting strenuous activities in temperature extremes. At present, research remains equivocal with regards to requirements of vitamin and minerals during field operations, but research indicates that there might be altered requirements for micronutrients under temperature extremes as a result of environmental stress impacting 151 intestinal absorption and/or increased utilization of some of these nutrients. Although, we were not able to demonstrate deficiencies of any micronutrients in our sample of CAF personnel, the studies show the risk for having less than recommended intakes of some micronutrients, which may have implications on health and performance of military personnel while operating long- term during field operations. 10.4 Higher than Recommended Intakes of Sodium In Chapter 6, we show that our sample of CAF military personnel had levels of sodium intake in excess of both the AI and UL from habitual diets and from ad libitum consumption of field rations. Both Chapters 7 and 8 illustrated that even under situations of partial consumption of rations, participants were consuming sodium amounts higher than AI and UL. Our finding of high sodium intake is similar to the sodium intake of the Canadian population 147 . Given the link between excessive sodium intake and hypertension, a risk factor for cardiovascular disease, the higher than recommended amounts of sodium intakes is potentially a cause for concern 148 . There has been significant emphasis on reducing the sodium content of Canadian foods and the sodium intake of the Canadian population, however, the DRI recommended levels do not take into account the increased amounts of sodium loss from skin through sweat during operations in temperature extremes. Although, we did not quantify the loss of sodium through sweat, our results from Chapter 7 indicate significantly less urinary output of sodium in the hot environmental treatment, which is likely a consequence of increased sweat production, in comparison to the sedentary and cold treatments. This may have implications for military personnel being able to tolerate extra sodium intake under situations of strenuous physical activities in temperature extremes 70,148 . Recommendations for sodium intake for military personnel have been demonstrated to be 5000 mg/day for male members, whereas recommendations for sodium content in operational rations can be up to 7000 mg/day as a result of military members being able to sustain sodium losses through sweat with varying levels of physical output while operating in the hot environment 70 . As a result, higher than recommended amounts of sodium from field rations during missions or operations may not be a cause for concern considering the low urinary sodium output and sodium losses via sweat. However, acclimatization to extreme temperature (e.g. heat) has resulted in reduced sodium in sweat and as such, military personnel may not require continual high intakes of sodium upon heat acclimatization 48,207 . Additionally, some studies have shown that individuals can acclimate 152 more rapidly to physical activity in the heat on a relatively restricted sodium intake 71,207 and consuming high levels of sodium may impede acclimatization 208 . This mechanism is attributed to a high sodium diet attenuating the aldosterone response associated with heat exposure in comparison to a low sodium intake, which augments this response 208 . Although, military personnel’s sodium requirements may be higher in comparison with an average healthy Canadian adult, research remains equivocal with respect to optimal sodium intake levels before, during and after operating or training in temperature extremes for military personnel. However, excess sodium intakes from habitual diets may still potentially have implications for adverse health and performance and impact operational readiness if these habits were to be continued. 10.4 Nutrient Intakes Similar Between Males and Females Due to the equal sample size of males and females during the winter weather field training in Chapter 8, our study was the first to explore, in a sample of CAF military personnel, whether there were any differences in nutrient intakes (from habitual diets and from field rations during the winter weather field training) between sexes. However, the study was not powered to detect differences in energy and nutrient intakes between males and females particularly due to changing demographics of the CAF. We found that female CAF personnel consumed energy in comparable amounts to that of male CAF members during field training. As such, interventions to optimize intake from rations during field operations should consider male and female soldiers as a group, rather than on sex basis. However, previous research has indicated that female soldiers may require higher intakes of specific micronutrients (e.g. iron or vitamin D) during combat training 47,183 . Further research may be warranted to better understand nutrient requirements, specifically micronutrients, of CAF female personnel. 10.5 Acute Operations in Environmental Extremes Impacts Nutritional Biomarkers Our findings in Chapter 7 indicated that despite a higher than recommended intake of sodium from field rations, operating in the hot climate resulted in significantly less urinary sodium output, thereby suggesting that military personnel may be able to tolerate extra sodium under such situations (even acutely). Similarly, operating in temperature extremes impacted urinary urea excretion that in turn can have an impact on altered protein utilization. In summary, an 153 acute period of subsisting on field rations did not have a measurable impact on blood biomarkers. However, the combined effect of operating strenuously under environmental stress (e.g. hot) is likely to impact some biomarkers (e.g. in this case urinary sodium and urinary urea). Whether subsisting on field rations for long-term impacts nutritional biomarkers still requires further exploration. 10.6 Novel Methods of Assessing Dietary Intakes of CAF Military Personnel Optimizing nutritional intake for military personnel is important in order to meet the high- energy demands of training and operations 2. Sufficient energy and nutrient intake promotes general health and reduces injury risk 2. Accurately understanding the nutritional requirements to sustain health and performance of military personnel is integral to ensuring their physiological and psychological wellbeing and operational readiness 130 . Limited data exists about the quantification of energy intake in Canadian Armed Forces (CAF) personnel, who are exposed to extremely challenging training and operations, where daily energy expenditures can be >6000 kcal/day 11,15,18,126 . However, collection of accurate and reliable dietary intake data (e.g. in the form of measured food intake/food waste) from military personnel is challenging in the field due to physical and cognitive stressors such as ambient temperature extremes, reduced sleep and heavy load carriage 2,11,31,110 . Most of the studies assessing intakes in CAF personnel operating in temperature extremes have used self-reported dietary assessment methodologies that are prone to misreporting bias 9,17,18 . In Chapter 8, we found energy intake to be similar between pre-study habitual diets (as assessed using the Canadian diet history food-frequency questionnaire (CDHQII)) and field ration consumption (as assessed using the measured food intake/food waste collection method) during the winter weather field training exercise. However, as has been shown by other researchers 103 , FFQs frequently underreport energy intake, as the intake reported using the FFQ in Chapter 8 (1961 kcal/day) was lower than the energy intake from habitual diets indicated in Chapter 6 (2657 kcal/day) measured using a 3-day weighed food record. Considering recent advancements and increases in adopting smart-phone technology, the use of tools such as mobile applications (apps), dietary trackers, and image capturing equipment may overcome some of the barriers 154 associated with traditional dietary assessment methods 109 and be particularly useful for military personnel in the field. Recent reviews have indicated that mobile phone technology is preferred by participants for recording dietary intakes over traditional methods, while offering additional benefits in reducing the burden related to coding and analysis time for the researchers 112,185 . The results in Chapter 9 demonstrated that a tablet app with integrated military ration nutritional information data was comparable to the traditional weighed food record method to assess dietary intakes in military personnel under non-operational settings. These novel findings indicate the benefits of mobile apps for conducting larger-scale studies of intake assessments in military personnel. Although promising as an alternate dietary assessment methods, the tablet app still needs to be validated in a larger sample size and under a variety of military operational settings of added physical and psychological stress. 10.7 Overall Limitations This thesis included convenience samples of 36 CAF personnel (18 Army Regular/Reservists in the simulation study and 18 Army Reservists in the winter weather field training study); therefore, our sample may not be representative across all CAF populations due to differential anthropometric measurements as well as type and trade of work variability. The level of physical activity per type/trade of work is likely to differ and hence, the extent to which our results may be biased by participants’ trade/level of physical activity in either direction is unknown. Additionally, our sample size for home, laboratory and field studies were small, which may limit the generalizability of our results across all of CAF population. However, our primary study was Chapter 7 and as such, the sample size calculation was based on detecting a 10% difference in energy intakes between treatments with 80% power at alpha of 0.05 for which we had more than sufficient number of participants. The study design in Chapter 7 was a repeated measures cross-over design, allowing for relatively increased statistical power with fewer subjects. In Chapter 6, we presented the nutritional intakes of a sample of CAF personnel under ‘habitual’ conditions, where we primarily focused on collecting energy and nutrient intake data at home. This data may not representative of military personnel living away from home but not deployed (e.g. in garrison or on reserves), where they may have different dietary patterns and food intake may differ. For example, CAF personnel living in garrison may not consume restaurant and fast- 155 food items to the same extent as CAF personnel under ‘home’ conditions. Additionally, the data on the proportion of participants below DRI or MDRI recommendations should be interpreted with caution due to the small sample size of the study and because the methods used to assess individual observed intakes may not be applicable to military personnel (e.g. within person variation likely to differ for these individuals when on field rations). Also, the MDRI recommendations are based for US military personnel98,99 and as such, the requirements, although similar, might be different for CAF personnel considering the different military doctrine and terrain/climate operating/training conditions. Future assessments of ‘usual’ nutrient intakes of CAF personnel would benefit from a larger sample size and data collection on more days of intakes. Additionally, field rations may or may not provide recommended intakes (MDRIs) of micronutrients depending on the combination, and components consumed were specific to 2013 menu items and may differ from items they would choose when operating or training in the field. While recognizing the methodological limitations of this study with regard to the individual nutrient intake assessments, our results in Chapter 6 are vital in terms of informing personnel of the importance of maintenance of nutrition under ‘home’ conditions and strategies to emphasize consumption of healthier food items, considering the recent survey reports of the potential rise in obesity and overweight in Canadian Forces 155 . In Chapter 7, our experimental protocol was designed to simulate field conditions, however, the artificiality of the environmental chamber likely influenced the results. For example, we found that participants consumed 70% of the total IMPs under these simulated conditions of extreme environmental temperatures and strenuous physical activity where participants had time to consume the field rations and were provided with prepared/cooked menu items on request. This percentage was high compared to the winter weather field training exercise, where less than 50% was consumed in the field. Additionally, participants were asked to only eat rations a total of three days per experimental treatment and palatability or ration monotony may not contribute to reduced energy intake in this acute setting, but the extent to which ration monotony may impact their intake on a longer-term basis is unknown. This study accounted for many of the tasks performed by the Canadian Army but we did not account for the military activities performed by Navy, Air Force or Special Forces. This likely limits the generalizability of the impact of strenuous physical activities on energy intakes across the varying trades and services of CAF population. Additionally, the demanding and strenuous nature of our experimental trial may also have influenced our results in either direction. This study was not designed to assess 156 the impact of prolonged strenuous physical activity in temperature extremes on nutrient intakes and hence, our results are not indicative of the periods of intense activity which may lead to additional energy deficits during long-term training or operations. In Chapter 8, our sample primarily consisted of CAF Reservists completing a basic military qualification training course and thus, this convenience sample may not be representative of the highly-active regular, reservists and rangers army personnel. Due to the constraints introduced as a result of field-based research in collaboration with Government and Military off-site, we were unable to fully control the experimental protocol and subject selection. Considering it was a basic qualification course, several participants were still learning the basic elements required to prepare/cook food during field conditions (e.g. having a propane fuelled grill), which may also have influenced their energy intake. The participants in this study were asked to refrain from additional foods and/or personal supplements and were solely restricted to the use of field rations for five days in the field. In comparison, soldiers deployed for missions or operations are likely consuming additional personal foods and supplements and/or may even be supplemented with fresh foods depending on the location, condition and availability of incremental allowances, thus the extent to which our results are over- or under-estimating energy intake in other CAF troops during harsh environmental conditions is unknown. Although, our study demonstrated voluntary anorexia under these conditions, it is limited by our ability to extrapolate to long-term effects during prolonged operations in harsh environmental temperatures on health and performance. In Chapter 9, our results were possibly influenced by the high compliance and ease of use of technology by our participants. Additionally, we did not assess the usefulness and accuracy of capturing nutrient intakes under conditions of psychological and physical stress in field conditions. Overall, our results have implications for energy deficits and voluntary anorexia for CAF personnel under harsh environmental conditions/locations. The results of this thesis warrants further consideration in accurate assessment and strategies to promote optimal nutritional intake in CAF personnel, but are limited by the small convenience sample size and constrained by the artificiality of the environmental chamber and operational logistics of conducting research during a real-life winter weather field training exercise. 157 Chapter 11 Future Directions 11.1 Research Nutrition-based research in military personnel should be aimed at optimizing physical and cognitive performance of CAF military members, to maximize their operational readiness, prior to and during deployment. Nutrition can play a significant role in meeting this need as insufficient dietary intakes can prolong recovery from illness and injury, depress immune function and impact physical and cognitive performance. The results of this thesis showcase many of the important research questions that should be addressed in studies evaluating dietary intakes of CAF military personnel. Overall, the evaluation should focus on two primary outcomes; first, the impact of long-term consumption of field rations on health and performance of CAF military personnel while operating or training for field missions in temperature extremes and demanding physical activity levels and, second, evaluating strategies to optimize dietary patterns and intakes of CAF military personnel consuming field rations for extended periods. 11.1.1 Determinants of Nutrient Requirements Results from Chapter 6 are the first in Canada to characterize the habitual dietary intakes of CAF military personnel. In situations where nutrient intakes may be less then ideal (e.g. during deployment), the nutritional status of the soldier prior to the period of low nutrient intake becomes a major determinant of nutritional status and subsequent performance 7. This applies particularly to energy and micronutrients (e.g. water soluble vitamins) that are not stored in the body 7. Thus, the operational readiness of a soldier is at risk of being compromised by suboptimal nutritional status prior to deployment. Therefore, it is essential to monitor the nutritional status of CAF members prior to deployment and determine how this may impact training or operations in the field. As demonstrated in Chapter 8, gender influences nutrient needs but predominantly through the body-size related difference rather than a sex-mediated difference. Thus, most of the energy 158 requirements difference (~20% as seen in Chapter 8) between males and females were accounted for by the body size and composition differences. However, research specifically aimed at the need for specific micronutrients (e.g. iron or calcium) is warranted to better understand the micronutrient requirements of serving female CAF military members. As illustrated in Chapter 7 and 8, temperature stress can exert influence on nutrient intakes and energy requirements. Although climate may have only a slight effect on macronutrient ratios across the range of environmental conditions that CAF military personnel are most likely to engage in during operations or training, environmental stress can have significant impacts on overall energy, micronutrient and hydration requirements. For example, Chapter 7 demonstrated the influence of heat on sodium requirements and, of cold on water requirements. Thus, future assessments on adequacy of energy, nutrient and hydration requirements from field rations in prolonged missions are essential. Furthermore, results from studies in other countries may not be applicable to CAF military personnel as our standard operating procedures, terrain, climate, ethnic mix, demographics and military doctrine are different than those of other Defence forces. Future research should aim to conduct studies on Canadian members deployed in typical training and operational situations to best determine CAF military nutrient requirements under range of operational requirements. Lessons learned from this research demonstrate that CAF military personnel likely have insufficient energy intakes in relation to the energy requirements and hence are at an increased risk for voluntary anorexia with potential negative consequences on performance and health. There is a need for research on strategies to increase the intakes of food and beverages during field missions and training in temperature extremes. 11.1.2 Nutritional Quality of Field Rations Results from this thesis indicate that the nutrient density of field rations could be enhanced to ensure that CAF military personnel are meeting the MDRI recommendations (considering higher requirements of CAF personnel during operating or training in the field and partial consumption of field rations) or exceeding these recommendations for some nutrients (e.g. protein). Combining the LMCs and/or supplementation with personal foods is likely to help enhance the nutrient profile of the IMPs. However, increasing the quantity of IMPs is not likely 159 to help combat the issue of discarding rations before deployment. As such, strategies to increase the nutritional density of field rations without additional menu items or reliance on personal foods and increasing the package weight are required. Although military personnel may be able to tolerate higher amounts of sodium in operational scenarios, especially in hot climates, there is paucity of research with regards to appropriate sodium levels while operating in cold climates. Sodium is an important food preservative given the long-self life (3 years) of field rations, however, clear sodium requirements for heat or cold acclimatization in relation to different levels of physical activity requires further investigation in CAF and military personnel in general. Although no studies thus far have looked at the impact of field rations on bowel habits of CAF soldiers, studies from other nations have demonstrated that consumption of field rations may impair bowel movements (e.g. constipation) and thus interfere with daily combat performance 141 . Additionally, anecdotal reports from our troops inform us of related bowel problems with long-term use of field rations. As demonstrated in this thesis, IMPs contain less than recommended amounts of fibre, which may play a role in adversely impacting soldier’s bowel habits (along with other factors such as the environmental condition or strenuous activities). However, higher than recommended amounts of fibre could interfere with tactical mobility in situations with limited water availability and where frequent bowel movements are undesirable 9. As such, future research should aim to determine the effect of field rations on bowel habits and potential ability of fibre to combat the problem of constipation in CAF military personnel exposed to high stress environments. It is possible that caffeine plays a contributory role in enhancing performance and cognitive abilities to sustain operational effectiveness, and thus, it is important to ascertain the effects of caffeine on cognitive and physical performance of CAF personnel. Beyond the food component of the field rations, maintaining adequate hydration levels is essential to effective performance. Data from Chapter 7 showed the significantly less water consumption by CAF participants in the cold treatment in comparison to the hot or temperate treatments. Thus, it will be important to investigate the water requirements and intake of CAF operating in the cold climates, since Canadian soldiers are likely to experience operations under such conditions. 160 Although much of the environmental nutritional and physiological research was conducted in the military after WWII 12 , there is paucity of research in recent literature regarding nutrition in Canadian military personnel. Considering the changing demographics of CAF personnel where reports have indicated that new recruits are less fit compared to previous generations 155 ; and advances in tactics/technologies related to operational duties in the ever-complex battlefield 209 , further research to determine adequate training requirements (including nutrition, physical fitness and appropriate sleep levels) is essential to optimize Canadian troops for operational readiness. 11.2 Policy The work presented in this thesis supports the development of nutrition-related policy in CAF troops aimed at improving the pre-deployment nutritional intake of military personnel and the need to investigate novel ways of ensuring adequate energy and micronutrients are consumed from field rations during field training or operations. This is particularly important as field rations are not consumed in their entirety. At a minimum, it suggests the need for emphasizing the importance of nutrition and adequate intakes of energy and micronutrients among CAF troops pre- and during deployment. However, the evidence also makes a strong case for a better understanding of the consumption patterns of soldiers and the need to implement policies to address insufficient energy intakes compared to energy requirements and the potential low intake of some micronutrients in CAF personnel in relation to strategies to overcome voluntary anorexia during training or operations. 11.2.1 Emphasis on Importance and Better Understanding of Nutrition CAF military personnel can benefit from nutritional guidance, especially in relation to the phenomenon of over- and under-feeding during field training and operations. Each trade, task and/or activity in specialized training or missions can pose differential nutrient requirements compounded by environmental factors (e.g. water availability, temperature, time to sleep or eat etc.). Introduction of soldier nutrition education material accompanying respective trades or operational conditions prior to deployment or training can help military personnel better assess and plan for their energy and nutrient requirements, especially during harsh environmental temperatures 75 . Additionally, promotion of nutrition particularly as it relates to health and 161 mental performance during command/pre-command courses could help emphasize the importance of diet to soldier performance during field conditions. 11.2.2 Using Technology to Better Understand Nutrition In Chapter 9, we demonstrated that using smartphone/tablet apps could help to assess dietary intakes of CAF military members and may overcome some of the barriers posed by traditional dietary assessment methods. Additionally, an electronic tool such as the tablet/smartphone that provided feedback, can also help military personnel better understand their food/nutrient consumption patterns, thereby potentially helping them to plan their energy and nutrient requirements in relation to field conditions. Since rations are a major source of nutrition during field conditions, CAF military personnel are likely to benefit by learning about the nutrient composition of these rations. An online database (ComRaD) of the nutrient composition of field rations available to US Army has shown potential to help guide soldiers on making ‘healthier’ and adequate nutrition choices, especially for field missions 210 . Such a tool has also the potential to benefit the CF dietitians in helping to plan fueling strategies for military personnel during field operations. Food intake apps like MyFitnessPal can be effectively linked to the database of nutrition information (e.g. ComRaD, as described above, or D/Food Svc nutritional composition of IMPs) to better help soldiers keep track of their nutrition during field operations and aid in future nutrition interventions to adequately fuel military personnel. Today, with the potential to combine mobile multimedia and wireless communication, 3- dimensional (3D) holographic wearable computing virtual reality devices are rapidly moving from conceptual to technological reality 211,212 . Military have actively employed virtual reality technology in simulating combat situations to help prepare soldiers for field operations. However, these devices could also provide a unique opportunity to quantitatively record and analyze food-intake in a real-time setting, without the need for manual input and time- consuming analyses of recorded dietary intakes 211 . However, most of this research is limited to assessing intakes of individual food items (e.g. apples), rather than combination of items. Future research in improving image-capturing of food and beverage intake using virtual reality devices is likely to aid in accurate assessments of dietary intakes. 162 11.2.3 Addressing Under-Consumption of Rations in Field Operations We have presented evidence that military personnel do not consume the field rations in their entirety and thus, are at risk of under-feeding in relation to energy requirements during field operations in harsh environmental conditions. Research has shown that several factors such as palatability/ease of consumption of ration menu items, water availability, time penalties, social facilitation, and environmental temperatures compound the problem of inadequate food intake in relation to energy requirements, although our data did not support reduced energy intake due to palatability, time to prepare or time to eat in an acute setting. Strategies to address under-consumption in field operations can include improvements in the following multifaceted factors 5,75 : 1) Education of the importance of nutrition for sustaining military operations 2) The potentially low intake of micronutrients might be improved by provision of fortified foods/beverage products (e.g. trail mixes, fruit/energy bars) 3) Increasing carbohydrates, preferably complex carbohydrates, and fibre intake can help sustain energy for both short and long-term missions and also improve digestion 4) Provision of easy-to-consume ‘on the go’ foods may help reduce the wastage and allow military personnel to carry adequate amounts of foods, given the tendency to ‘strip’ the field rations prior to training or deployment 5) Addressing ration factors including ration monotony, hedonic ratings, nutrient density and meal variety; 6) Fluid intake levels to ensure adequate hydration status; 7) Social factors including addressing the importance of nutrition under the influence of unit commander and attitudes of the individual soldier towards rations; 8) Situational factors including facilitating the time to eat, group eating and meal scheduling; 9) Environmental factors including provision of packaging or elements to protect food items from hot/cold or ability to heat the components of the rations and; 10) Psychological factors including time to sleep or feeling secure from enemy action. In summary, a broad approach that addresses ration acceptability, ration consumption, temporal/logistical factors and field eating environment situations is required to overcome ration under-consumption and mitigate the effects of voluntary anorexia. 163 Chapter 12 Key Findings and Implications The following section summarizes the key findings from this thesis and the potential implications of these findings: Key Finding #1: Reduced energy intake is not due to ration palatability; time to eat or prepare the food in an acute setting. Implications: This finding suggests investigations into novel ways of ensuring sufficient energy intake in relation to requirements during short-term field operations or training, when CAF personnel are consuming field rations or IMPs. Key Finding #2: A convenience sample of CAF military personnel demonstrated less than recommended intakes of some micronutrients from habitual diets and from self-selected consumption of field rations. Implications: This finding has implications for potential compromises in physical performance and health due to less than optimal intakes of micronutrients under conditions of higher requirements if the field rations are consumed exclusively for a long period of time and not in their entirety. Lower than recommended intakes of some nutrients prior to deployment has implications for compromised operational readiness of CAF soldiers, as the nutritional status of the individual prior to the period of low-nutrient intake (e.g. during deployment) itself becomes a determinant of nutritional status and may subsequently impact performance. Key Finding #3: A convenience sample of CAF military personnel demonstrated similar energy intake in a laboratory study (in treatments of increased physical activity levels and temperature stress in comparison to a sedentary temperate treatment). Participants did not increase their energy intake during subsequent meals once the stress of temperature and activity had subsided. Implications: This finding may have implications for insufficient energy intake in relation to the energy expenditures of CAF personnel performing strenuous physical activities under prolonged exposure to temperature extremes. 164 Key Finding #4: A convenience sample of CAF military personnel exhibited voluntary anorexia from insufficient intake in relation to the energy provided and expended during a winter weather field training exercise, resulting in a significant body weight loss. Implications: This finding has implications for deficits in performance and health of military personnel under longer duration operations, thereby, potentially compromising the operational readiness of CAF soldiers. Key Finding #5: Using technology (e.g. a tablet app or a smartphone app) could offer a mobile alternative to assessing dietary intakes in a population of CAF military personnel in the field or during training. Implications: This result has implications for more easily acquiring accurate dietary assessments of CAF military personnel in field operations, under varying temperature and operational requirements. 165 Chapter 13 Conclusions This thesis demonstrated the likely insufficient energy and nutrient intakes of a convenience sample of CAF personnel engaged in demanding military-specific physical activities and in temperature extremes in relation to energy requirements. In addition, CAF participants consumed less than recommended amounts (compared with EARs and MDRIs) of some micronutrients, depending on the combination and the amount of the menu items consumed. This thesis also characterized habitual dietary intakes of a convenience sample of CAF military personnel and demonstrated some CAF personnel consume less than their recommended intakes of some micronutrients from their habitual diets. Additionally, CAF military personnel are consuming simple sugars and sodium in excess of recommendations, which may have implications on their overall health. Finally, this thesis demonstrated the potential benefits of using mobile technology to assess dietary intakes in military personnel consuming field rations in the field. This research indicates the need for development and promotion of strategies to increase the energy and nutrient intake of military personnel training or operating in the field under harsh conditions. Under conditions of voluntary anorexia, strategies to increase food intake while providing more nutrient dense foods would be beneficial. 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Appendices Appendix A: Field Ration Menu Items (Experimental Treatments) Field Rations Menu Items Offered During Simulated Experimental Treatments MENU ITEMS and MEAL TYPES Menu Item # Menu Item Description Meal Type 1 Sausage and Hash Browns Breakfast 2 Hash Browns and Bacon Breakfast 3 Baked Beans Breakfast 4 Breakfast Sausages Breakfast 5 Scalloped Potatoes and Ham Breakfast 6 Beans and Wieners Breakfast 7 Cheese Tortellini with Bolognese Sauce Lunch 8 Sweet and Sour Pork Lunch 9 Smoked Meat with Demi-Glace Sauce Lunch 10 Thai Chicken Lunch/Dinner 11 Beef Stroganoff Lunch 12 Salmon Lunch 13 Chilli Dinner 15 Chicken a la King Dinner 14 Meatloaf with Onion Sauce Dinner 17 Lamb and Vegetable Stew Dinner 18 Lasagne Dinner A sample military field ration (IMP) 182 183 Appendix B: Field Ration Menu Items (Meaford) Field Rations Menu Items Offered During the Winter Weather Field Training Exercise MENU ITEMS and MEAL TYPES Menu Item # Menu Item Description Meal Type 1 Sausage and Hash Browns Breakfast 2 Hash Browns and Bacon Breakfast 3 Baked Beans Breakfast 4 Breakfast Sausages Breakfast 5 Scalloped Potatoes and Ham Breakfast 6 Beans and Wieners Breakfast 7 Hamburger Lunch 8 Veal Cutlet with Mushroom Sauce Lunch 9 Shepherd’s Pie Lunch 10 Chicken Pesto Pasta Lunch/Dinner 11 Chicken Cannelloni Lunch 12 Chicken Cordon Bleu Lunch 13 Chilli Dinner 15 Chicken a la King Dinner 14 Meatloaf with Onion Sauce Dinner 17 Lamb and Vegetable Stew Dinner 18 Tarragon Chicken Dinner 184 Appendix C: Assessment of Habitual Dietary Intake of Canadian Armed Forces Personnel Using the Modified Healthy Eating Index Abstract Submitted to Canadian Nutrition Society Conference Montreal, May 24-28, 2017 Assessment of Habitual Dietary Intake of Canadian Armed Forces Personnel Using the Modified Healthy Eating Index Ahmed M, Mandic I, Goodman L, Jacobs I and L’Abbé M. Introduction: Beyond specific nutrient intake recommendations, a measure of overall diet quality is useful to evaluate the nutritional health of population groups. The Healthy Eating Index (HEI) is a measure of diet quality applied in United States but has been modified for Canada in concordance with the recommendations of the Canada’s Food Guide (CFG). Although the HEI has been applied to military personnel in United States, the diet quality of Canadian Armed Forces (CAF) personnel is unknown. The objective of this study was to use the modified-HEI as a tool to characterize, in a sample of CAF personnel, the quality of their habitual diets. Methods: Dietary intake of 18 male and female CAF (mean age 34 y), participating in a laboratory metabolism and feeding study, was assessed using the weighed food record. Modified-HEI scores were calculated by tabulating the data for the four CFG categories (total vegetables and fruits, total grain products, milk and alternatives and meat and alternatives). Other components (whole fruit, dark green and orange vegetable, whole grains, sodium and saturated/unsaturated fats) were calculated using the identification of foods in Health Canada’s CFG and ESHA nutrient composition software, using CNF2015 data. ‘Other foods’ were classified as any food other than those in the above food groups and tabulated per participant. Results: 185 The average score was 55 out of 100 points, which is similar to general Canadian population and is defined as a diet that requires improvement. The components of the HEI on which CAF participants scored high were meats and alternatives (9 out of 10) and unsaturated fats (8 out of 10). Participants had lower scores on fruits and vegetables, grain products, milk and alternatives, and sodium, and consumed 29.6% of total energy from ‘other foods’, which lowered the overall score. Conclusion: Modified-HEI can be a useful tool to identify military personnel with lower diet quality. This may provide the opportunity to target interventions such as diet education in an effort to improve the health and performance of CAF personnel before deployment. Research Support: Research contract awarded to principal investigator I. Jacobs by Defence Research and Development Canada Appendix D: Incremental Allowances Examples of Incremental Allowances 11 : Dispersed Meals are authorized to offset the additional food expenditures required to satisfy the soldiers on the field. These meals include Box Lunch, Hot Pack, Hay Boxes and Flight Meals. The Field Feeding Allowance is authorized during operations and/or exercises and provides additional nutritional requirements necessary to support strenuous physical activity and longer working hours. The allowance is dependent on the number of soldiers as well as the duration of the exercise/operation. The Infrequent Meals Allowance is authorized when freshly prepared meals are provided irregularly and is comprised of freshly prepared meals (e.g. dining room meals/ BBQs) on a weekly basis. The Extra Calories Increment Allowance is authorized under the following conditions: during deployment of operational/training units in arduous conditions undergoing high physical demands, for Reserve Force summer camps and for personnel engaged in training activities. The Between Meal Allowance is authorized under the following conditions: when personnel are engaged in operations and exercises of arduous conditions with exposure to extreme heat (above 30 degrees Celsius) or cold (less than 0 degrees Celsius), when soldiers are unable to acquire snacks/drinks from camps, for hospital/clinic patients, during flight travel, for air traffic controllers, communication research operators, meteorological technicians and air crew personnel. The Deployed Operations Allowance is authorized when personnel operate 16-24 hours per day, 7 days a week and is composed of both night snacks and workplace refreshments. The IMP supplement allowance is authorized by the requesting unit’s commanding officer when soldiers have subsisted entirely on IMPs for up to and over 13 consecutive days. It comprises snacks such as coffee/tea, soup, crackers, bread, peanut butter/jelly, muffins or granola as well as fresh fruits and vegetables. The Fresh Ration Supplement Allowance is only authorized under Multinational or Allied feeding situations and takes into account the different standards of other nations. 186 Appendix E: Food Satisfaction Surveys Food Satisfaction Survey Results (During Chapter 6 and 7) A) By Meal Type (that is by breakfast, lunch and dinner): A Kruskal-Wallis H test showed that there was no significant difference in ease of preparation/consumption and food preparation and preparation time between the different meal types (χ 2 = 0.47, 0.88, 1.5, 0.02, respectively), p>0.05 (See Boxplots 1-4). A Kruskal-Wallis H test showed that there was no significant difference in taste, texture, variety, quantity, saltiness, sweetness, density/fullness, digestibility and overall adequacy between the different meal types, (χ 2 =2.3, 0.1, 0.03, 0.06, 0.08, 0.08, 0.05, 0.6, 0.01), p>0.05 (See Boxplots 5-13). Overall, the menu items within the breakfast, lunch and dinner were scored largely acceptable in the different categories (ease of preparation/consumption, food preparation/preparation time, taste, texture, variety, quantity, saltiness, sweetness, density/fullness, digestibility and overall adequacy) with a few at borderline acceptability. 187 188 Boxplot 1: Ease of Preparation was scored largely acceptable. Boxplot 2: Ease of Consumption was scored as largely acceptable. 189 Boxplot 3: Food Temperature was scored as largely acceptable. Boxplot 4: Food Preparation time was considered largely acceptable. 190 Boxplot 5: Variety of menu items scored as largely acceptable. Boxplot 6: Quantity of menu items were scored as largely acceptable with two participants ranking breakfast menu items as either completely acceptable or borderline acceptable. Some participants scored some Lunch and Dinner menu items as largely or completely unacceptable. 191 Boxplot 7: Taste of menu items within breakfast, lunch and dinner were scored as largely acceptable. However, lunch menu items were scored as a range from completely unacceptable to completely acceptable. Boxplot 8: Texture of menu items within breakfast, lunch and dinner were scored as largely acceptable. 192 Boxplot 9: Saltiness menu items within breakfast, lunch and dinner were scored as largely acceptable. Boxplot 10: Sweetness of menu items within breakfast and lunch were scored as largely acceptable. Menu items in the Dinner meal were considered as borderline acceptable. 193 Boxplot 11: Density and Fullness menu items within breakfast, lunch and dinner were scored as largely acceptable . Boxplot 12: Digestibility menu items within breakfast, lunch and dinner were scored as largely acceptable. 194 Boxplot 13: Overall adequacy of menu items within breakfast, lunch and dinner were scored as largely acceptable. Individual participants ranked breakfast menu items from completely unacceptable to completely acceptable. B) By Menu Items (that is by individual menus): A Kruskal-Wallis H test showed that participants found Sausage and HashBrowns to be significantly different in ease of preparation (χ 2 =32.1) and food preparation time (χ 2 =30.6) in comparison with other menu items (p<0.05). Participants also found Sausage and HashBrowns to be sweeter (χ 2 =25.8) in comparison with other meals (p<0.05). Although not statistically significant, participants ranked Salmon and Chili higher for taste (Rank 87, 100), texture (Rank 97, 91) and ease of consumption (Rank 94, 83) in comparison with other meals. Below, the boxplots describe each menu item in relation to Ease of consumption/preparation, food preparation/preparation time, taste, texture, variety, quantity, saltiness, sweetness, digestibility, density and fullness and overall adequacy. 195 Boxplot A: Ease of Preparation: Menu # 11, 12, 13 (Beef Stroganoff, Salmon and Chili) ranked constant at 5 (completely acceptable) and Menu # 1 (Sausage and HashBrowns) ranked constant at 3 (borderline acceptable). Only one participant ranked #13 Chili as 4 (largely acceptable) and #2 HashBrowns and Bacon as 2 (largely unacceptable). 196 Boxplot B: Ease of Consumption: Menu # 5 (Scalloped Potatoes and Ham) ranked constant at 4 (largely acceptable) but the boxplot shows three participants as outliers ranking the item as 5 (completely acceptable), 3(borderline acceptable) or 2 (largely unacceptable). One participant ranked menu #7 Cheese Tortellini with Bolognese Sauce as largely unacceptable. Although menu # 8 Sweet and Sour Pork was ranked constant as 4 (largely acceptable), two participants ranked it as either 5 (completely acceptable) or 3 (borderline acceptable). One participant ranked # 10 Thai chicken as completely unacceptable. Menu # 11, 12 ,13 (Beef Stroganoff, Salmon and Chili) were at 5 (completely acceptable) except Menu # 11 was ranked as 4 (largely acceptable) or 2 (largely unacceptable) by two participants and Menu # 13 was ranked as 4 (largely acceptable) by one participant. 197 Boxplot C: Food Temperature: Menu # 1 (Sausage and HashBrowns) ranked constant at 1 (completely unacceptable) and only one participant ranked it as 4 (largely acceptable). Menu # 4, 11, 13 (Breakfast Sausages, Beef Stroganoff and Chili) remained constant at 5 (completely acceptable) except one participant ranked it as menu # 11 and 13 as 4 (largely acceptable). 198 Boxplot D: Food Preparation Time: Menu # 1 (Sausage and HashBrowns) ranked constant at 3 (borderline acceptable) with one participant ranking it as 4 (largely acceptable). Menu # 2, 11, 12, 13 (Hashbrowns and Bacon, Beef Stroganoff, Salmon and Chili) remained constant at 5 (completely acceptable) but two participants ranked menu # 2 and 13 as largely acceptable. 199 Boxplot E: Variety: Menu # 1 (Sausage and HashBrowns) ranked constant at 3 (borderline acceptable) with two participants ranking it as 5 (completely acceptable) or 2 (largely unacceptable). One participant ranked Menu # 3 (Baked Beans) as 3 (borderline acceptable). Menu # 9 (Smoked Meat with Demi-Glace Sauce) remained as 3 (borderline acceptable). Menu # 13 (Chili) was ranked as 5 (completely acceptable) with one participant ranking it as 4 (largely acceptable). 200 Boxplot F: Quantity: Menu # 1 (Sausage and HashBrowns) ranked constant at 3 (borderline acceptable) with one participant ranking it as 5 (completely acceptable). Menu # 4, 6, 16 (Breakfast Sausages, Beans and Wieners and Meatloaf with Onion Sauce) ranked as 4 (largely acceptable). One participant ranked menu # 5 (Scalloped Potatoes and Ham) as 3 (borderline acceptable). Two participants ranked menu # 6 (Beans and Wieners) as 3 (borderline acceptable) or 5 (completely acceptable). One participant ranked menu # 13 (Chili) as 1 (completely unacceptable) and one participant ranked menu # 16 (Meatloaf with Onion Sauce) as 5 (completely acceptable). Boxplot G: Taste: Menu # 2,3,6,8,10 (Hashbrowns and Bacon, Baked Beans, Beans and Wieners, Sweet and Sour pork and Thai Chicken) ranked at 4 (largely acceptable). (Sausage 201 and HashBrowns) ranked constant at 3 (borderline acceptable) with one participant ranking it as 5 (completely acceptable) with two participants ranking them as either 5 (completely acceptable), 3 (borderline acceptable) or 2 (largely unacceptable). Two participants also ranked Menu # 5(Scalloped potatoes and ham) and #10 (Thai Chicken) was also ranked as 1 (Completely unacceptable). 202 Boxplot H: Texture: Menu # 2,3 (Hashbrowns and Bacon and Baked Beans) ranked at 4 (largely acceptable). Two participants ranked menu # 2 (Hashbrowns and Bacon) and #10 (Thai Chicken) as 5 (completely acceptable). Menu # 2 (Hashbrowns and Bacon) was also ranked as 3 (borderline acceptable) by one participant. 203 Boxplot I: Saltiness: Overall, menu items were ranked borderline to largely acceptable with saltiness. 204 Boxplot J: Sweetness: Overall, menu items were ranked borderline to largely acceptable with sweetness. 205 Boxplot K: Density and Fullness: Participants considered menu items to be largely acceptable as dense and fulfilling. 206 Boxplot L: Digestibility: Participants considered menu # 2,3,8,16 (Hashbrowns and Bacon, Baked Beans, Sweet and Sour Pork and Meatloaf with Onion Sauce) as largely acceptable in digestibility but overall menu items were scored as borderline acceptable. 207 Boxplot M: Overall Adequacy: Menu items were scored largely acceptable in overall adequacy. C) Comments and Concerns: On Bread, Tortillas and Corn-Bread: “Where is the corn bread? Corn bread is better than the bread” – BS-09 “Will be better with tortillas instead of bread” – BS-09 “Tortillas here great!” – CJ-10 On Macronutrients: “Lack of Protein” – MF-04, SL-02, BS-09 “The menu has too many calories and not enough protein. Compare to my shake or even my normal food I was feeling crappy and without/lack of energy”- MF-04 On Saltiness and Sweetness: 208 “Too sweet and salty” - MF-04, WR-06, SL-02, KS-07, CJ-10 On Digestibility: “Gassy all day, I was uncomfortable” – SL-02 “More Fiber Needed” – PE-20 On Preparation, Packaging and Utensils: “Ration Heater should come inside IMP” – MF-04, KBS-27 “For the field in my opinion there is too much packing and regulatory stuff i.e. why provide a spoon, should all be equipped with knife, fork, spoon, paper towel. Herb sauce. Add value apart from flavour” – SL-02 “Should add fork, knife as plastic cutlery”– MF-04 “Again due to a busy schedule during the lunch I ate late and didn't have time to prepare the meal so ate the oreos and tortillas while on the move. As previously stated I believe the lunch menu should be made up of more on the go food that can be snacked while working” – SL-02 “No Prep time” – MJ-15 On Quantity: “These meals are okay when stationary but you go hungry when on the move” - WR-06 “Not Enough” – SL-02 “Could eat more” – KBS-27