Isolating and Exploiting the Mechanisms That Link Breakfast and Human Health - Intervention

Study Overview
=================
Brief Summary
-----------------
Following the establishment of causal links between breakfast consumption, the individual components of energy balance, and health it is now important to examine and target the underlying biological mechanisms involved to maximise potential health benefits. To begin investigating the outlined mechanisms healthy, non-obese participants will be recruited to take part in phase I (acute design) of a wider project.

Detailed Description
-----------------
Causal links between breakfast consumption, the individual components of energy balance, and health have recently been established and it is now important to examine and target the underlying biological mechanisms over a longer period of time to maximise potential health benefits. Specifically, the substitution of a portion of carbohydrate for protein at breakfast may enhance the potential health benefits of breakfast through targeting distinct mechanistic pathways. Broadly, introducing a greater protein load at breakfast increases insulin secretion and delays gastric emptying, thereby eliciting a potentiated insulin response. In turn this may therefore improve glucose tolerance during a subsequent meal. Additionally, maintenance of euglycaemia following breakfast consumption, coupled with the thermic effect of feeding protein may accentuate the elevated energy expenditure following breakfast observed in previous studies. Finally, both the physical and chemical properties of protein exert a marked satiating effect. Collectively, these mechanisms could interact to maximise the net impact of breakfast on energy balance and associated health outcomes. However, whilst the evidence indicates obvious benefits of feeding a higher protein dose at breakfast, relatively little research has focused on the response to protein over multiple meals/days. Furthermore, and importantly, the mechanisms involved in the second-meal phenomenon and the potential for initial meals of varied composition to target these mechanisms have never been systematically investigated. To begin investigating the outlined mechanisms healthy, non-obese participants will be recruited to undergo a 4 week intervention study in which they will consume one of three breakfasts for 28-days. The breakfast interventions provide will be: Carbohydrate rich breakfast Whey protein enriched breakfast Extended morning fast Participants will undergo 7 days of habitual physical activity and diet monitoring prior to visiting the laboratory for their preliminary metabolic assessment in which they will consume the carbohydrate rich breakfast followed by an ad libitum meal for lunch. They will then be randomised to one of the 3 breakfast interventions for 28-days. During the 28-days weekly monitoring of physical activity and energy intake will take place in order to assess energy balance. Upon completion of the intervention phase participants will revisit the laboratory to replicate the initial visit in which postprandial metabolism was assessed.

Official Title
-----------------
Isolating and Exploiting the Mechanisms That Link Breakfast and Human Health - Intervention

Conditions
-----------------
Physical Activity, Postprandial Metabolism, Weight Loss

Intervention / Treatment
-----------------
* Other: Carbohydrate Rich Breakfast
* Dietary Supplement: Whey protein enriched breakfast


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Body mass index 18.5-29.9 kg∙m-2 Age 18-65 years Able and willing to provide informed consent and safely comply with study procedures Females to maintain record of regular menstrual cycle phase or contraceptive use No anticipated changes in diet/physical activity during the study (e.g. holidays or diet plans) Inclusive to all breakfast habits (e.g. regular skipper / consumer) Exclusion Criteria: Any reported condition or behaviour deemed either to pose undue personal risk to the participant or introduce bias Any diagnosed metabolic disease (e.g. type 1 or type 2 diabetes) Any reported use of substances which may pose undue personal risk to the participants or introduce bias into the experiment (e.g. smoking/substance abuse) Lifestyle not conforming to standard sleep-wake cycle (e.g. shift worker) Any reported recent (<6 months) change in body mass (± 3%)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be randomised to one of 3 intervention arms.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Carbohydrate rich breakfast<br>Participants will be provided with 28-days worth of pre-weighed carbohydrate rich breakfast materials to consume before 1000h daily. | Other: Carbohydrate Rich Breakfast<br>* Participants will be asked to consume the provided carbohydrate rich breakfast before 1000h daily for 28 days.<br>|
| Experimental: Whey protein enriched breakfast<br>Participants will be provided with 28-days worth of pre-weighed whey protein enriched rich breakfast materials to consume before 1000h daily. | Dietary Supplement: Whey protein enriched breakfast<br>* Participants will be asked to consume the provided whey protein enriched breakfast before 1000h daily for 28 days.<br>|
| No Intervention: Extended morning fast<br>Participants will be asked to remain fasted (i.e. to not consume breakfast) until 1200h daily for 28-days. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in physical activity thermogenesis | Energy expenditure measured using physical activity monitor | Assessed for 1 week at baseline, 3 days a week during weeks 1-3 of the intervention and again for 1 week in the 4th week of the intervention. | 
| Change in expression of circadian clock genes measured in whole blood | Pre and post intervention change clock gene expression | Baseline and 4-weeks | 
| Change in postprandial glycaemia following carbohydrate rich test breakfast and lunch over 4 weeks | The postprandial time course response of plasma glucose to the test breakfast and lunch meals | Baseline and 4-weeks | 
| Change in postprandial insulinaemia following carbohydrate rich test breakfast and lunch over 4 weeks | The postprandial time course response of plasma insulin to the test breakfast and lunch meals | Assessed at baseline and after 4 weeks of the intervention | 
| Change in body mass | Participants will be weighed prior to the intervention and again upon completion | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in postprandial incretin hormone response following breakfast and lunch | The postprandial time course response of plasma incretin hormones (e.g. GLP-1 & GIP) to the the test breakfast. | Baseline and 4 weeks | 
| Change in subjective appetite ratings following breakfast and lunch | Ratings of appetite provided on subjective appetite scales (on a scale of 0-100 mm where 0 is associated with lower ratings and 100 with higher ratings) following the test breakfast and lunch | Baseline and 4 weeks | 
| Change in fuel oxidation during the test breakfast | Fat and carbohydrate oxidation following breakfast | Baseline and 4 weeks |