The Big Breakfast Study

Study Overview
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Brief Summary
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This weight loss study will investigate the impact of diet composition and meal size (large breakfast meals and smaller evening meals) on body weight, energy balance and eating behaviour, by altering calorie (meal) distribution.

Detailed Description
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The aim of this study is to further strengthen our understanding of the role of dietary components (in particular fibre and protein) in a healthy diet. The information gained from this research will lead to better policy advice, particularly in relation to healthy weight management, metabolic control, mental health and intestinal health. It will also lay the foundations to produce healthier primary products and aid the food industry in developing new and healthier products (e.g. products that aid hunger control and satiety). This will be addressed through four interlinked objectives: O1: Healthy weight management and improved metabolic and mental health O2: Identification of gut bacteria and compounds of relevance to vascular and gut health O3: Linking fibre consumption to intestinal microbial communities and health O4: Mathematical modelling of interactions between diet and gut microbial communities

Official Title
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Role of Breakfast Size and Composition for Appetite Control and Energy Balance

Conditions
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Obesity, Weight Loss

Intervention / Treatment
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* Other: High Fibre
* Other: High Protein


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI ranging from 27-42 kg/m2; those habitually consuming breakfast (at least 5 times a week). Exclusion Criteria: women who are pregnant, planning to be pregnant or breastfeeding subjects with food allergy diagnosis of diabetes, hypertension, renal, hepatic, haematological disease or coronary heart disease having given a pint of blood for transfusion purposes within the last month unsuitable veins for blood sampling inability to understand the participant information sheet inability to speak, read and understand the English language those on any prescription medications (other than oral contraceptives) those on any specific diet regimes those on any weight loss programmes (that may be affecting lifestyle, physical activity and diet).

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Fibre to High-Protein (HF-HP)<br>Phase 1: no intervention, habitual diet for 4 days and then 3day maintenance diet Phase 2: consumption of HF meals for 4 weeks Phase 3: washout for 1 week, controlled maintenance diet Phase 4: consumption of HP meals for 4 weeks | Other: High Fibre<br>* High fibre/carbohydrate (50% CHO, 35% fat and 15% Protein) with 45% calories at breakfast and 20% evening meal provided and buffet lunch. Total dietary fibre will be at least 30g/d for 2000kcal intake and provided as a mixed soluble and insoluble fibre sources to maintain palatability of the diet (e.g. wheat bran, fava bean, lentil, buckwheat).<br>* Other names: HF;Other: High Protein<br>* • High protein diet (30% protein, 35% fat and 35% CHO) with 45% calories at breakfast and 20% evening meal provided and buffet lunch. Protein will be a mixed meat matrix to include poultry, fish, red meat, prawns, eggs, dairy. Total dietary fibre will be no more than 15g/d for 2000kcal intake.<br>* Other names: HP;|
| Experimental: High Protein to High-Fibre (HP-HF)<br>Phase 1: no intervention, habitual diet for 4 days and then 3day maintenance diet Phase 2: consumption of HP meals for 4 weeks Phase 3: washout for 1 week, controlled maintenance diet Phase 4: consumption of HF meals for 4 weeks | Other: High Fibre<br>* High fibre/carbohydrate (50% CHO, 35% fat and 15% Protein) with 45% calories at breakfast and 20% evening meal provided and buffet lunch. Total dietary fibre will be at least 30g/d for 2000kcal intake and provided as a mixed soluble and insoluble fibre sources to maintain palatability of the diet (e.g. wheat bran, fava bean, lentil, buckwheat).<br>* Other names: HF;Other: High Protein<br>* • High protein diet (30% protein, 35% fat and 35% CHO) with 45% calories at breakfast and 20% evening meal provided and buffet lunch. Protein will be a mixed meat matrix to include poultry, fish, red meat, prawns, eggs, dairy. Total dietary fibre will be no more than 15g/d for 2000kcal intake.<br>* Other names: HP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Energy Balance | Chronic influence on energy balance (body weight, kg) | measured up to day 71 of study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute effects on appetite after test meals | Appetite questionnaires recorded on Visual Analogue Scales every 30mins on test days | Baseline & week 4 of each treatment | 
| Acute effects on biomarkers of health after test meals | blood samples analysed for Glucose, Lipids and Hormones | Baseline & week 4 of each treatment | 
| Acute effects on gastric emptying after test meals | gastric emptying (stable isotope, Octanoic acid labelled breath samples) | Baseline & week 4 of each treatment | 
| Resting Metabolic Rate (RMR) before & after test meals | Chronic influence on metabolism or Thermic Effect of Food (TEF) using indirect calorimetry measurement | Baseline & week 4 of each treatment | 
| Faecal sample analysis for gut health | Chronic influence on changes in gut microbiota | up to 10 weeks | 
| Bone Density | Dual Energy X-ray Absorptiometry (DXA) Scan to measure fat mass, fat free mass & bone density as part of the 4 compartment model | Baseline & week 4 of each treatment | 
| Body Composition | Air Displacement Plethysmography (BodPod) to measure body fat as part of the 4 compartment model | Baseline & week 4 of each treatment | 
| Total Body Water | Deuterium Dilution to measure Total Body Water (TBW) as part of the 4 compartment model | Baseline & week 4 of each treatment |