Lifestyle Diseases: Group Diet and Physical Activity Intervention in the Workplace
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Reduction of risk for lifestyle diseases: Group diet and physical activity intervention in the workplace. Michelle Brenda Cumin Master of Applied Science Auckland University Of Technology Auckland June, 2004 Acknowledgements A huge thank you to each of the wonderful men and women who volunteered to participate in this study for their time, bodies, co-operation and feedback. A special thanks to Elaine Rush and Vishnu Chandu who gave of their time and expertise to carry out the hundreds of measurements needed over the period of the study. Thank you to Professor Lynn Ferguson, my cosupervisor for her help and encouragement and to Dr Lindsay Plank for all his help. Thank you too to Stephanie Schulz for her help with the blood samples and the general flow of measuring days and to the phlebotomists from Medlab particularly Linda who did most of the blood tests. Thank you to the BCMRC team, including Manaia Laulu, Minaxi Patel, Naita Puniani, Vishnu Chandu, Amanda Jordan and the many students, both undergraduate and post- graduate who taught me heaps along the way. Thank you to all the administrative staff at AUT including Heather Stonyer, Benneth Gilbert and Annette Tiaiti for their help and advice. Thank you to my husband Mike and children, David and Tracey for letting me study with them. I would like to acknowledge the generous support of the Auckland University of Technology, Science and Engineering Faculty postgraduate student’s contestable research grant and the Zespri International for the supply of the kiwifruit used in this study. Last and most importantly, my thanks and appreciation to my supervisor Associate Professor Elaine Rush PhD for her encouragement, knowledge, help, advice, mentorship, friendship and sharing. Without her this study would never have taken place. " What the teacher is, is more important than what he teaches." Karl Menninger ii Abstract Background Cardiovascular disease is a major cause of death in most Westernised countries.The prevalence of obesity, type 2 diabetes mellitus and cancers is rapidly increasing. Older people with elevated blood lipids, obesity and DNA damage are at high risk of developing these diseases. There is a plethora of research to support the claim that a healthy diet and increased physical activity can reduce the risk of increased body fatness, diabetes and generally improve health. However most interventions require intensive one to one advice. The aim of this study was to measure the effect of a group approach to advising on changes in lifestyle with particular attention to foods high in fibre. The study spanned a period of 12 weeks with a follow up session at 52 weeks to ascertain sustainability. The study This study was a 12 week longitudinal intervention study with a follow up after 52 weeks. Measurements of anthropometry (skinfolds, girths, weight and height), blood pressure, body fat by bioimpedance and fasting blood (lipids, glucose and insulin) were made at weeks 0, 3, 6, 9,1 2 and 52. The participants were asked to complete a food frequency questionnaire and a physical activity questionnaire at each of the 6 measuring sessions and to provide an indication of what the goals that they had set and if they had accomplished them after 9,12 and 52 weeks. Between measurements at weeks 0 and 3 the volunteers were left to follow their usual food and activity pattern. Then as a group they were given a diet and exercise talk and provided with written material and pedometers to increase motivation. After measurement at week 6 they were randomly divided into two groups. The first group (A) were prescribed and provided with kiwifruit at a dose of 100g/30 kg body weight for three weeks while the second group (B) continued with the changes in diet and physical activity. Following measurement at week 9 group A abstained from kiwifruit while Group B added the kiwifruit to their diet and the measurements repeated. After 52 weeks, with only emails as ongoing communication, they were remeasured. iii Results For this multicultural, relatively middle aged group of 53 staff (28 women, 25 men) of mean age 46 years, measurable and statistically significant metabolic gains were made in the lipid profile over 12 weeks. Total cholesterol, LDL cholesterol, triglycerides and the ratio of total cholesterol to HDL all decreased and HDL increased significantly. Total cholesterol decreased from 5.6(±1.1) mean(±SD) mmol/L at baseline to 5.3(±1.1) mmol/L at week 12 (p<0.001); LDL cholesterol decreased from 3.5(±0.97) mmol/L at baseline to 3.3(±0.94) mmol/L at week 12 (p<0.001); and total cholesterol to HDL ratio decreased from 4.0(±1.1) to 3.7(±0.9) (p<0.001). In the 36 who were measured at 52- week follow- up these changes persisted. With the other outcome measures glucose showed a statistically but not biologically significant decrease over the 12 week period and body composition, blood pressure and insulin showed no significant change. The kiwifruit crossover had no apparent affect on the measures of any of the measurements reported. The participants reported that they increased fruit and vegetable and oily fish consumption and increased physical activity. These increases took place over the initial 12 week period and were maintained over 52 weeks. Conclusion This study has shown that changes in diet and physical activity can favourably influence blood biochemistry even without accompanying changes in percentage body fat and weight. Furthermore, small, manageable lifestyle changes can result in biochemical changes persisting over 52 weeks. iv Table of Contents Title page(unnumbered) i Acknowledgements ii Abstract iii Table of contents v List of figures viii List of tables ix Statement of originality x Abbreviations xii 1 Introduction 1 2 Literature Review - Lifestyle Diseases 8 2.1 Obesity 8 2.2 Hypertension 12 2.3 Cardiovascular Disease 14 2.4 Type 2 Diabetes Mellitus 17 2.5 Cancer 20 2.6 Summary 23 3 Literature Review - Diet and Physical Activity-Relationships to the development of lifestyle diseases 24 3.1 Diet 24 3.1.1 Carbohydrates 25 3.1.1.1 Glycaemic Index 26 3.1.1.2 Dietary Fibre 27 3.1.1.3 Fruit and vegetables 30 3.1.1.4 Kiwifruit- a high nutrient density fruit 31 3.1.2 Dietary Fat 32 3.1.2.1 Omega-3 Fatty Acids 33 3.1.2.2 Saturated Fatty Acids 35 3.1.3 Sodium 36 3.2 Physical Activity 37 3.2.1 Background 37 3.2.2 Strategies for increasing physical activity 38 3.2.2.1 Pedometers 39 3.2.3 Physical activity, with & without diet in the treatment of lifestyle disease 40 3.2.3.1 Obesity - physical activity and diet effects 41 3.2.3.2 Cardiovascular disease - physical activity and diet effects 42 3.2.3.3 Type 2 diabetes mellitus - physical activity and diet effects 45 3.2.3.4 Cancer - physical activity and diet effects 45 3.3 Summary 46 4 Literature Review - Large Studies -Prospective and Controlled Interventions 47 4.1 Background 47 4.1.1 Prospective studies 47 v 4.1.2 Intervention studies 50 4.2 Summary 57 5 Literature Review - Choice of Design and Methodologies 58 5.1 Methods of imparting knowledge - group vs individual 58 5.2 Anthropometrics 59 5.2.1 Body mass Index (BMI) 60 5.2.2 Waist 61 5.2.3 Skinfolds 61 5.3 Bioelectrical Impedance Analysis (BIA) 62 5.4 Blood biochemistry 65 5.4.1 Homeostasis Model Assessment (HOMA) 66 5.4.2 Fasting plasma lipids, glucose and insulin 67 5.5 Questionnaires 67 5.5.1 Food Frequency Questionnaires 68 5.5.2 Physical Activity Questionnaires 69 5.6 Other health assessment methods 70 5.7 Comet assays 70 5.8 Summary 71 6 Method 74 6.1 Design 74 6.1.1 Recruitment 75 6.1.1.1 Retention 75 6.1.2 Measurements 77 6.1.2.1 Anthropometry 78 6.1.2.2 Blood measurements 81 6.1.2.3 Bioelectrical Impedance Analysis (BIA) 82 6.1.2.4 Blood pressure 82 6.1.2.5 Questionnaires 82 6.1.3 Forms 83 6.1.3.1 Protocol sheets 83 6.1.4 Diet and exercise 'shake up' 84 6.1.4.1 Booklets 85 6.1.5 Kiwifruit 86 6.1.6 Statistics 86 7 Results 88 7.1 Participants 88 7.2 Anthropometric measures 91 7.3 Obesity risk factors 93 7.4 Hypertension 94 7.5 Cardiovascular disease 97 7.6 Type 2 diabetes mellitus 99 7.7 Kiwifruit crossover 101 7.8 Questionnaires 101 7.9 Physical Activity 104 7.10 Best and worst results 109 vi 7.11 Case studies 111 8 Discussion and Conclusion 116 8.1 Discussion 116 8.1.1 Participants 116 8.1.2 Body composition 117 8.1.3 Blood pressure 120 8.1.4 Lipid profile 120 8.1.5 Glucose and insulin 122 8.1.6 Cancer 123 8.1.7 Reported changes in food and activity 123 8.2 Limitations of this study and recommendations for further interv 127 8.2.1 Limitations 127 8.2.2 Suggestions for improvements 131 8.2.2.1 Improvements to the methods 132 8.2.2.2 To the advice given 133 8.2.3 What was achieved? 134 8.2.4 Subsequent studies and future research 135 8.2.5 Suggestions for participants to facilitate change 136 8.3 Conclusion 137 References 138 Appendices 163 1a Ethics approval 164 1b Ethics approval extension 165 2 Consent form 166 3 Protocol sheet 167 4 Electrode placement for BIA 168 5 Food frequency questionnaire 169 6a Physical Activity Questionnaires 178 6b Goal sheet questionnaire 1 179 7 Goal sheet questionnaire 2 182 8 Kiwifruit questionnaire 185 9 Information booklet for group shake-up 186 10 Recipes 196 11 Diet calculations 210 12 Powerpoint presentation- group shake-up 211 vii List of Figures Figure 2.1 Joint National Committee hypertension categories (JNC-V) 12 Figure 5.1 Timeline and design of intervention study 73 Figure 6.1 Points of skinfold measurements 79 Figure 7.1 Bar charts (mean and SE) showing changes in lipid profile 100a (A- upper graph) and diabetes risk factors (B-