An interventional study of Big Breakfast and Big Dinner in Obesity and Weight Loss, sponsored by University of Aberdeen. Completed at 1 site in United Kingdom. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-04-06.
Sponsored by University of Aberdeen · Not applicable, Interventional, and Treatment
This weight loss study will investigate the impact of calorie distribution across a day (large breakfast meals and smaller evening meals versus small breakfast meals and large evening meals) on body weight, and physiological and behavioral mechanisms regulating energy balance.
Participants will undergo 2 x 4 week energy restriction protocols in a randomized cross over design; big breakfast (45% of calories in the morning meal, 20% at dinner) and big dinner (45% of calories in the evening meal, 20% at breakfast). We predict that timing of eating will influence energy balance, because morning energy expenditure is amplified in comparison to the evening. This study will allow us to assess whether the increased energy expenditure in the morning is linked to natural biological circadian rhythm or behavioral adaptions.
Dietary advice for weight management is broadly based on the assumption that a 'calorie is a calorie' and it does not matter when calories are consumed across the day. Recent evidence has challenged this assumption, suggesting that we may utilize calories more efficiently when consumed in the morning relative to the evening, and this could be used as a beneficial strategy for weight loss - this is a newly developing field of investigation which merges circadian biology with nutrition (chrono-nutrition).
Timing of food consumption is a modifiable factor influencing energy balance and body weight (and thus, disease risk). Previous research has shown that calories ingested at different times of the day have different effects on energy utilization, leading to differential weight loss, even at iso-caloric amounts. This study will aim to increase our understanding of the underlying behavioral and physiological mechanisms associated with differential weight loss and energy balance when calories are consumed predominantly in the morning versus in the evening.
This study will be a cross-over study comparing large breakfast versus large evening meals (percent daily calories split between breakfast, lunch and dinner as 45-35-20 (breakfast-loaded) or 20-35-45 (evening-loaded)) during energy restriction (Fed to measured RMR) on energy balance, through differences in both physiological and behavioural changes in energy expenditure and substrate utilization.
Exclusion Criteria:
Phase 1: no intervention, habitual diet for 4 days and then 4day maintenance diet Phase 2: consumption of BB energy restriction diets for 4 weeks Phase 3: washout for 1 week, controlled maintenance diet Phase 4: consumption of BD energy restriction diets for 4 weeks
Other: Big Breakfast · Other: Big Dinner
Phase 1: no intervention, habitual diet for 4 days and then 4day maintenance diet Phase 2: consumption of BD energy restriction diets for 4 weeks Phase 3: washout for 1 week, controlled maintenance diet Phase 4: consumption of BB energy restriction diets for 4 weeks
Other: Big Breakfast · Other: Big Dinner
Weight loss diet (Calories fed to measured RMR) with calories distributed predominantly at breakfast (percent daily calories split between breakfast, lunch and dinner as 45-35-20%). The diet will be high protein (30% protein, 35% fat and 35% CHO) with all meals provided.
Weight loss diet (Calories fed to measured RMR) with calories distributed predominantly at dinner (percent daily calories split between breakfast, lunch and dinner as 20-35-45%). The diet will be high protein (30% protein, 35% fat and 35% CHO) with all meals provided.
Energy balance
Change in energy balance during each diet protocol (body weight (kg))
Time frame: Measured up to day 71 of study
Total Daily Energy Expenditure
Total energy expenditure measured by DLW for the 4 week BB and BD diet phases
Time frame: 4 x 2 weeks. Throughout weeks 2-5 and 7-10.
Resting Metabolic Rate (RMR)
RMR measured with indirect calorimetry (ventilated hood)
Time frame: Baseline,week 1, week 5, week 6, week 10.
Thermic effect of food (TEF)
TEF measured with indirect calorimetry (ventilated hood) for 6 hours after a breakfast meal
Time frame: Week 1, week 5, week 6, week 10.
Body Volume
Measured with Air Displacement plethysmography (BODPOD),
Time frame: Week 1, week 5, week 6, week 10.
Bone Mineral Content
Measured with Dual energy x-ray absorptiometry (DEXA)
Time frame: Week 1, week 5, week 6, week 10.
Total Body Water
Measured with deuterium dilution
Time frame: Week 1, week 5, week 6, week 10.
Body Composition
4 compartment model to assess changes in body composition (Combined from the measures of body weight, body volume, total body water and bone mineral)
Time frame: Week 1, week 5, week 6, week 10.
Gastric emptying
Gastric emptying measured using stable isotope, Octanoic acid labelled breath samples.
Time frame: Week 1, week 5, week 6, week 10.
Waist and hip circumference
Change in waist and hip circumferences and waist to hip ratio
Time frame: Week 1, week 5, week 6, week 10.
Gut appetite hormones
Change in plasma fasting and 2 hr post-meal appetite hormones
Time frame: Week 1, week 5, week 6, week 10.
Plasma glucose
Change in plasma fasting and 2 hr post-meal glucose
Time frame: Week 1, week 5, week 6, week 10.
Plasma insulin
Change in plasma fasting and 2 hr post-meal insulin
Time frame: Week 1, week 5, week 6, week 10.
Blood lipids
Change in plasma fasting and 2 hr post-meal blood lipids
Time frame: Week 1, week 5, week 6, week 10.
Daily Subjective Appetite
Changes in subjective appetite (hunger, fullness, desire to eat) measured using visual analogue scale questionnaires every waking hour for 3 days.
Time frame: Hourly measures for 3 days in week 1,week 5, week 6, week 10.
Postprandial Subjective Appetite
Changes in subjective appetite (hunger, fullness, desire to eat) measured using visual analogue scale questionnaires every 30 minutes for 6 hours after test meals.
Time frame: Week 1, week 5, week 6, week 10.
Faecal sample analysis for gut health
Chronic influence on changes in gut microbiota
Time frame: Week 1, week 5, week 6, week 10.
Physical activity
Change in physical activity levels measured with accelerometer (actigraph)
Time frame: Measured continuously for 24 hours for 3 days in week 1,week 5, week 6, week 10.
24 hour blood glucose
Changes in 24 hour blood glucose levels measured with a continuous glucose monitor
Time frame: Measured continuously for 24 hours for 3 days in week 1,week 5, week 6, week 10.
Plan to share: No
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University of Aberdeen