Isolating & Exploiting the Mechanisms That Link Breakfast to Human Health - Acute

Study Overview
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Brief Summary
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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 crossover design) of a wider project.

Detailed Description
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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 involved to maximised 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 take part a randomised crossover trial that will contrast the acute metabolic responses to a protein-enriched breakfast, with a carbohydrate rich breakfast, and the total omission of breakfast.

Official Title
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Isolating & Exploiting the Mechanisms That Link Breakfast to Human Health - Acute

Conditions
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Postprandial Metabolism, Appetite

Intervention / Treatment
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* Other: Carbohydrate rich breakfast
* Dietary Supplement: Whey protein enriched breakfast


Participation Criteria
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Eligibility Criteria
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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
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Minimum Age: 18 Years
Maximum Age: 65 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
Interventional Model Description: Participants will complete 3 breakfast feeding trials in a randomised order: Typical high carbohydrate breakfast followed by an ad libitum lunch. Whey protein enriched carbohydrate followed by an ad libitum lunch. Extended morning fast followed by an ad libitum lunch.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Carbohydrate rich breakfast<br>Participants will consume a porridge breakfast that is considered in line with typical carbohydrate consumption for this meal. | Other: Carbohydrate rich breakfast<br>* A porridge breakfast meal fed at a carbohydrate delivery rate of 7.3 mg/kJ of each participants resting metabolic rate.<br>|
| Experimental: Whey protein enriched breakfast<br>Participants will consume a porridge breakfast that is considered in line with typical carbohydrate consumption for this meal. | Dietary Supplement: Whey protein enriched breakfast<br>* A porridge breakfast meal in which 15 grams of whey protein is substituted in place of carbohydrate and a small portion of fat.<br>|
| No Intervention: Extended morning fast<br>Participants will extend their overnight fast until the ad libitum lunch is provided. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial glycaemia following breakfast | The postprandial time course response of plasma glucose to each breakfast meal | Plasma glucose time course data over 3 hours following breakfast | 
| Postprandial insulinaemia following breakfast | The postprandial time course response of plasma insulin to each breakfast meal | Plasma insulin time course data over 3 hours following breakfast | 
| Postprandial glycaemia following ad libitum lunch | The postprandial time course response of Plasma glucose to the ad libitum lunch following each type of breakfast | Plasma glucose time course data over 2 hours following lunch | 
| Postprandial insulinaemia following ad libitum lunch | The postprandial time course response of plasma insulin to the ad libitum lunch following each type of breakfast | Plasma insulin time course data over 2 hours following lunch | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial incretin hormone response following breakfast | The postprandial time course response of plasma incretin hormones (e.g. GLP-1 & GIP) to the each breakfast. | Plasma insulin time course data over 3 hours following breakfast | 
| Postprandial incretin hormone response following ad libitum lunch | The postprandial time course response of plasma incretin hormones (e.g. GLP-1 & GIP) to the ad libitum lunch following each type of breakfast | Plasma incretin time course data over 3 hours following breakfast | 
| Subjective appetite ratings following breakfast | Ratings of appetite provided on subjective appetite scales following each type of breakfast. On a scale of 0-100mm with 0 typically being associated with lower subjective ratings and 100 being associated with higher subjective ratings. | For 3 hours following each breakfast | 
| Subjective appetite ratings following ad libitum lunch | Ratings of appetite provided on subjective appetite scales following ad libitum lunch. On a scale of 0-100mm with 0 typically being associated with lower subjective ratings and 100 being associated with higher subjective ratings. | For 3 hours following the ad libitum lunch | 
| Fuel oxidation following breakfast | Fat and carbohydrate oxidation following each type of breakfast | For 3 hours following breakfast | 
| Fuel oxidation following ad libitum lunch | Fat and carbohydrate oxidation following ad libitum lunch | For 2 hours following the ad libitum lunch |