The development of a functional food breakfast and its effects on gluco-regulation, cognitive performance, mood and satiety in adolescents. Sarah Kennedy Oxford Brookes University This thesis is submitted in partial fulfilment of the requirements of the award of Doctor of Philosophy July 2016 1 Acknowledgements I have been incredibly lucky to have the help and support of many wonderful colleagues and friends who were unbelievably willing to take time away from their own research to assist with the school studies. A quick mention really does not go far enough to express how grateful I am to the following people for their support and friendship: Marta Campolier, Patricia Shaw, Georgios Saltaouras, Alaaddine El-Chab, Samiah Kokandi, Shelly Coe, Miriam Clegg, Majd Jan, Ameerah Almaski, Kimberly Harcourt, Jon Kennedy, Sarah Graham, Rick Varnham, Ann Fraser, Jilly Martin and Sarah Hillier. Thank you to all the students and staff from Oxford Brookes who contributed to the development and running of the school study days: Abby Whyte, Sally Morey, Charlie Field, Claudia Preston, Emma Young, Abi Barclay-Watt, Trudy Ing and John Brierley. Pete Robins for the loan of the equipment and Lauren Nicoll for her help with the data entry. Thank you also to Donna Isaac, Jacky Ward and Dean Woodham for being so accommodating and to all the students who took part in the study. Working with adolescents was certainly an interesting and entertaining experience. I have had the guidance and support of two wonderful supervisors Dr Miriam Clegg and Dr Lisa Ryan. I am forever grateful for all your encouragement, advice and inspiration over the past few years. A big thank you to all my friends and family who have had to suffer my dashing around, bringing work on holidays and having a general lack of commitment to any social event. Special thanks go to Win Kennedy for her expert help and advice and to Emma Davies for her valuable input. Lastly, I have to thank my wonderful husband, for his endless help and support and for keeping me fed, laughing and sane. I dedicate this to him, Rowan and Tonylama. 2 Abstract It is well documented that eating a regular breakfast is associated with benefits to markers of metabolic health and cognitive performance. The composition of breakfast differentially affects the metabolic response which may also have implications for cognitive performance. To date, much of the research on gluco-regulation is in adults, and no studies have investigated the effects of a functional-food breakfast (FB) on gluco-regulation and cognitive performance, mood and satiety in adolescents. Therefore, this thesis aims to address this research gap through the implementation of a series of five research studies. The primary aim was to investigate the effects of a FB which included ingredients selected for their potential to improve gluco-regulation (blueberries, baobab, cinnamon and oats) on measures of gluco-regulation (glucose response (GR) and insulin response (IR)) compared to a control breakfast (CB), and ready to eat cereal (RTEC) (adults only). Secondary aims were to measure: cognitive performance (using a map recall and delayed word recall task), mood (using the 'Activation–Deactivation Check List’) and satiety (using VAS scales). Measures were collected at timed intervals over a three-hour period after the three breakfasts. The study was first implemented in healthy adults (n=16, 32.0±10.0 years) in a controlled laboratory environment and found that consumption of the FB resulted in a lower glucose peak and a lower IR AUC, compared to the CB and RTEC (p<.05) (chapter 6). In a school environment, adolescents' (n=22, 13.7±0.5 years) consumption of the FB reduced peak glucose, peak insulin and IR AUC at 60 and 120 minutes, compared to the CB (p<.05) (chapter 7). There were no effects on cognitive performance, mood or satiety regardless of breakfast condition (p>.05). Two preliminary studies (chapter 3 and 4) contributed to aspects of the FB and CB development (chapter 5) and breakfast study design (chapter 6 and 7). In chapter 3, validation of a novel portable indirect calorimeter in adults (n=20, 38.3 ±11.2 years) resulted in the revision of the main hypothesis (chapter 2), where investigations into the effect of the FB on energy expenditure (EE) 3 was discontinued. In chapter 4, the completion of a breakfast-based questionnaire by adolescents (n=434, 13-15 years) informed the choice of ready to eat cereal (RTEC) on which the breakfast conditions were based (chapter 5). Additionally, these studies made individual contributions to the literature reporting the use of indirect calorimetry in schools to collect body composition measures from adolescents (n=30) (chapter 3) and highlighting implications for the design of breakfast interventions in adolescents (chapter 4). Findings from this thesis suggest that the addition of functional food ingredients to breakfast has the potential to improve gluco-regulation in healthy adults and adolescents. The inclusion of functional food ingredients as part of breakfast should be considered alongside the promotion of breakfast. 4 List of Abbreviations AD Active diet FM Fat mass AUC Area under the curve FRAP Ferric ion reducing antioxidant power ANOVA Analysis of variance GI Glycaemic index ANCOVA Analysis of covariance GL Glycaemic load BBB Blood-brain barrier GR Glycaemic response Brain-derived neurotrophic Health Behaviour of School-aged BDNF HBSC factor Children BMI Body mass index IGT Impaired glucose tolerance BMR Basal metabolic rate IR Insulin response International Organization for BQI Breakfast quality index ISO Standardization CB Control breakfast IWHS Iowa Women’s Health Study CHO Carbohydrate LED Light-emitting diode CNS Central nervous system LNAA Large neural amino acids CV Coefficient of variation LOA Limit of agreement CVD Cardiovascular disease MCI Mild cognitive impairment CHD Coronary heart disease MRMR Measured resting metabolic rate National Health and Nutrition Deltatrac DT NHANES Examination Survey Daily breakfast National Health and Medical Research DBC NHMRC consumption Council DIT Diet-induced thermogenesis NO Nitric oxide DOH Department of Health NMDA N-methyl-D-aspartate EB Breakfast consumption OB Breakfast omission European Food Safety Oxford Brookes University EFSA Authority OBU EE Energy expenditure OR Odds ratio Food and Agricultural FAO PA Physical activity Organisation FB Functional food breakfast PBC Perceived behavioural control FCR Folin-ciocalteu reagent PCA Principal components analysis FFM Fat free mass PHE Public Health England 5 Predicted resting metabolic PRMR rate RCT Randomised control trial RDS Rapidly digested starch REE Resting energy expenditure RMR Resting metabolic rate RQ Respiratory quotient RTEC Ready-to-eat cereal SBP School-breakfast programmes SCFA Short-chain fatty acids SD Standard deviation SDS Slowly digestible starch SES Socio-economic status SEM Standard error of mean SN Subjective norms T2DM Type 2 diabetes mellitus TPB Theory of planned behaviour TRP Tryptophan U.S. Department of USDA Agriculture VAS Visual analogue scale VCO2 Volume of carbon dioxide VO2 Volume of oxygen WHO World Health Organisation 6 Publications 1. Kennedy S, Ryan L, Fraser A, Clegg ME. A comparison of indirect calorimeters' measures of resting metabolic rate. Proc Nutr Soc. 2013; 72 (OCE3):E155. 2. Kennedy S, Ryan L, Fraser A, Clegg ME. Comparison of the GEM and the ECAL indirect calorimeters against the Deltatrac for measures of RMR and diet-induced thermogenesis. J Nutr Sci. 2014; 3(e52):1-11 (Appendix 1). 3. Kennedy S, Ryan L, Clegg ME. Associations between breakfast consumption, attitudes towards breakfast and physical activity in adolescents. Proc Nutr Soc. 2015; 74 (OCE1):E99. 4. Kennedy S, Ryan L, Clegg ME. The effect of a functional food based breakfast on blood glucose response, insulin response, and satiety. Abstract/Appetite. 2015; 91:431-439 5. Kennedy S, Ryan L, Davies EL, Clegg ME. Applying an extended Theory of Planned Behaviour to predict breakfast consumption in adolescents. Eur J Clin Nutr. 2017; 71(5):607-613. 7 Table of Contents Acknowledgements ............................................................................................................................................................................... 2 Abstract .................................................................................................................................................................................................. 3 List of Abbreviations ........................................................................................................................................................... 5 Publications ........................................................................................................................................................................................... 7 Table of Contents ................................................................................................................................................................ 8 Appendix list ..................................................................................................................................................................... 16 List of figures .................................................................................................................................................................... 17 List of tables .....................................................................................................................................................................