Placebo Breakfast Consumption, Appetite and Food Intake

Study Overview
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Brief Summary
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The purpose of this study was to examine the effects of a very low-energy, viscous placebo breakfast meal on subjective appetite sensations during the morning, and food intake at lunch, compared to a typical whole-food breakfast meal and a water-only control. Participants will not be told that the placebo breakfast contains nearly no energy until the end of the study. The breakfasts will be provided in a randomised order, with a period of at least four days separating the trials. Blood samples will be taken before and after the breakfast is eaten to see how appetite-regulating proteins and blood sugars respond during the morning. Appetite questionnaires will also be completed throughout the morning, and a pasta-based lunch meal will be provided so that voluntary food intake can be measured.

Detailed Description
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Obesity is a risk factor for several chronic diseases, including type-2 diabetes, heart disease and some forms of cancer. There is clear evidence demonstrating that weight gain occurs progressively over the lifespan, highlighting that preventative action should be taken by young, lean individuals, who may yet develop overweight or obesity later in life. A positive energy imbalance, in which energy intake exceeds energy expenditure for a sustained duration, is known to be the underlying systematic cause of obesity. Therefore, reducing daily energy intake is a seemingly simple solution to the this problem. However, compensatory alterations in appetite regulation which stimulate an increase in energy intake often impede the long-term success of such interventions. Extending the overnight fasting period, thereby restricting the time available for food intake, has emerged as an effective dietary strategy for reducing daily energy intake and may assist with weight management. Laboratory studies have shown that skipping breakfast typically results in increased appetite during the morning, and an increase in energy intake at lunch. Therefore, the long-term success of skipping breakfast may be reduced by elevated appetite sensations. A recent study which aimed to assess the effects of a very-low energy, placebo breakfast on resistance exercise performance noted that appetite was suppressed after consuming the placebo, despite its lack of energy content. Whether this suppression of appetite following placebo breakfast consumption results in a reduced energy intake at lunch, is currently unknown. Therefore, the investigators are interested to examine the subjective and hormonal appetite responses to placebo breakfast consumption, compared with these responses to an overt breakfast consumption trial an overt breakfast skipping trial, and whether these changes result in any differences in voluntary energy intake at lunch. The present study is a randomised, controlled, crossover study in which fourteen healthy, habitual breakfast-consuming (self-reported) males will consume a very low-energy, viscous placebo breakfast, a typically consumed, whole-food breakfast, and a water-only control. At least four days will separate trials. Participants will firstly complete a pre-screening session in which anthropometric data will be collected. This will be used to determine the energy content of the typical whole-food breakfast.

Official Title
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Effect of the Perception of Breakfast Consumption on Appetite and Energy Intake in Healthy Males

Conditions
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Obesity

Intervention / Treatment
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* Dietary Supplement: Placebo breakfast
* Dietary Supplement: Typical whole-food breakfast
* Dietary Supplement: Water-only control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-smoker. Habitually consuming breakfast at least 3 days per week. Have maintained a stable weight for 6 months (self-reported). No known history of gastric, digestive, cardiovascular or renal disease. Exclusion Criteria: Food allergies, dislike or intolerance of study foods or drinks. Not currently on a weight management program or have irregular eating patterns (i.e. extended fasting periods >8h other than overnight - self reported). Use of medication that may affect hormone concentrations. Excessive alcohol consumption (>4 units/day). Intensive training schedule (>10 hours/week).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

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: The study design is a randomised, controlled, crossover design in which participants undertake three dietary conditions in a randomised order with at least a four day period in between trials.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Very low-energy, viscous placebo breakfast<br>Participants will consumed a viscous breakfast meal from a standard bowl with a standard spoon. The volume of the meal will be 5 mL/kg body mass, consisting of 15% (0.75 mL/kg body mass) low-energy flavoured squash, with the remainder made up of tap water. To thicken the solution and increase the perception of energy intake, 0.1 g/kg xanthan gum (a soluble fibre often used as a low-energy thickening agent) will be added and the mixture will be blended thoroughly. An additional 3 mL/kg tap water will be consumed as a drink alongside the meal in this trial. | Dietary Supplement: Placebo breakfast<br>* Participants will consume a very low-energy, placebo breakfast meal, but will be unaware of its near complete absence of energy until the end of the study.<br>|
| Active Comparator: Typical, whole-food breakfast<br>Participants will consume a standardised meal consisting of puffed rice cereal, semi-skimmed milk, white bread, seedless strawberry jam, and apple juice. This meal will provide 20% of estimated energy requirements, determined by multiplying estimated resting metabolic rate by a physical activity level of 1.6. A measured volume of tap water will be consumed alongside this meal, in order to match total water content of the typical whole-food breakfast to the very low-energy, viscous placebo breakfast. | Dietary Supplement: Typical whole-food breakfast<br>* Participants will consume a typical whole-food breakfast meal, equating to 20% of estimated energy requirements.<br>|
| Active Comparator: Water-only control<br>Participants will consume 8 mL/kg body mass of plain tap water to match the total water content of the typical whole-food breakfast and the very low-energy, viscous placebo breakfast. | Dietary Supplement: Water-only control<br>* Participants will consume a volume of plain water to match the water content of the very low-energy placebo breakfast and the typical whole-food breakfast.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Voluntary energy intake (Kilocalories) at a laboratory-based test lunch meal | A laboratory-based meal consisting of pasta, tomato sauce and olive oil will be provided to participants in excess of expected consumption. Participants will be permitted 20 minutes to eat as much or as little as they desire, until 'comfortably full and satisfied'. | 195 minutes post-breakfast provision. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analogue Scale for Subjective Ratings of Appetite | Time-course of subjective ratings of hunger between breakfast provision and one hour after consuming lunch, measured using an appetite visual analogue scale. The scale is divided into subscales of different appetite perceptions including: hunger, fullness, desire to eat and prospective food consumption. Each subscale is rated on a 100mm scale (i.e. from 0 - 100), with a rating of 100 fully supporting the perception and a rating of 0 fully opposing the perception. | Baseline, 10 minutes, 30 minutes, 60 minutes, 120 minutes, 195 minutes, 215 minutes, 275 minutes post-breakfast provision. | 
| Acylated ghrelin | Time-course of acylated ghrelin plasma concentrations across experimental trials. | Baseline, 60 minutes, 180 minutes post-breakfast provision. | 
| Peptide tyrosine-tyrosine (PYY) | Time-course of PYY plasma concentrations across experimental trials. | Baseline, 60 minutes, 180 minutes post-breakfast provision. | 
| Blood glucose concentration | Time-course of blood glucose concentrations across experimental trials. | Baseline, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes post-breakfast provision. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breakfast skipping, Energy intake, Energy balance, Appetite hormones, Placebo feeding