Acute Time-Restricted Eating in Young Healthy Males

Study Overview
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Brief Summary
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This study compared the metabolic response to three different eating windows (morning fast,12pm-8pm; evening fast, 8am-4pm; control, 8am-8pm).

Detailed Description
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Humans have evolved as a diurnal species, internally governed by the circadian system, which dictates our hormone regulation. 'Chrononutrition' is a sub-discipline which combines food timing with circadian physiology. The most popular method of time-restricted feeding in the UK is to skip breakfast. However, data from several meta-analysis have shown that skipping breakfast is associated with weight gain and insulin resistance, likely due to eating later into the evening/night and therefore, out of sync with our circadian rhythm. Recent research has shown that skipping dinner (evening fasting) has improved markers of cardio-metabolic health in clinical populations, although these are typically from longer-term studies. Despite these promising findings, it is not yet known whether these findings are population specific. Therefore, the investigators are interested in examining the metabolic response pre and post-intervention to see whether these promising findings can translate into a healthy population. Furthermore, the investigators will be monitoring subjective appetite, energy intake, and expenditure to assess whether there is any short-term adaptation to a specific feeding window.

Official Title
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The Effect of Acute Time-Restricted Eating on Energy Intake, Subjective Appetite and Glycaemic Control in Young Healthy Males

Conditions
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Obesity Prevention

Intervention / Treatment
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* Behavioral: Evening Fasting
* Behavioral: Morning Fasting
* Behavioral: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: recreationally active non-smokers non-dieting weight stable (self-reported for >6 months) were not consuming any medication known to affect appetite or physical activity Exclusion Criteria: Smokers >10 hours per week physical activity Have dieted within the past 6 months Excessive alcohol consumption (>14 units/week) Use of medication or supplements that may affect hormone concentrations.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: The study design is a randomised, controlled, crossover design in which participants undertake three conditions in a randomised order with at least one week in between trials.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Evening Fasting<br>Participants will undertake acute evening fasting (feeding between 8am-4pm) | Behavioral: Evening Fasting<br>* Participants will undertake acute evening fasting (feeding between 8am-4pm) for one day. After which they will attend the laboratory, following a 16 h fast, where baseline measures will be taken and the response to a standardised meal will take place. The participant will also have an opportunity to feed ad-libitum before they leave the laboratory.<br>|
| Experimental: Control<br>Participants will undertake an acute standard western feeding pattern (feeding between 8am-8pm). | Behavioral: Control<br>* Participants will undertake an acute standard western feeding pattern (feeding between 8am-8pm). After which, participants will visit the laboratory the following day, after a 12 h fast, where baseline measures will be taken and the response to a standardised meal will take place. The participant will also have an opportunity to feed ad-libitum before they leave the laboratory.<br>|
| Experimental: Morning Fasting<br>Participants will undertake an acute morning fasting trial (feeding between 12pm-8pm). | Behavioral: Morning Fasting<br>* Participants will undertake an acute morning fasting trial (feeding between 12pm-8pm). After which, participants will visit the laboratory the following day, after a 16 h fast, where baseline measures will be taken and the response to a standardised meal will take place. The participant will also have an opportunity to feed ad-libitum before they leave the laboratory.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glycaemic Control | A metabolic assessment lasting 3.5 hours will take place following a standardised, laboratory-based meal. The investigators will be taking periodic capillary and venous blood samples to measure post-prandial glucose and insulin, which together comprise 'glycaemic control'. | 0 hour (Pre breakfast), 1 hour, 2 hour, 3.5 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Energy Intake | Energy intake will be measured both during lab and outside of the laboratory when the participants are free-living. During lab, energy intake will be measured through ad-libitum feeding buffet where 20 minutes will be permitted to eat as much or as little as they desire, until 'comfortably full and satisfied', followed by post-feeding measurement of the remaining food. | 3.5 hour following breakfast | 
| Energy expenditure | Energy expenditure will be measured via a chest-worn device (Actiheart) which combines heart rate and accelerometry to gauge calories expended. | Activity recorded across day 1 standardisation and day 2 (lab visit and post lab visit) | 
| Visual analogue scale for subjective ratings of appetite | Subjective appetite will be measured on mobile devices via a software which replicates a 100mm visual analogue scale. The scale is divided into subscales of different appetite perceptions including: hunger, fullness, desire to eat and prospective food consumption. This will be measured on a scale of 0-100 (0 - none at all) (100 - a lot). | 0 hour (pre-breakfast), 1 hour, 2 hour, 3 hour, 4 hour (post breakfast during lab visit) | 
| Acylated Ghrelin (Appetite hormone) | Acylated Ghrelin will be measured from the venous samples taken during the post-prandial period following the standardised meal. | 0 hour (pre breakfast), 1 hour, 2 hour, and 3 hour post breakfast | 
| PYY (Appetite hormone) | Acylated Ghrelin will be measured from the venous samples taken during the post-prandial period following the standardised meal. | 0 hour (pre-breakfast), 1 hour, 2 hour, and 3 hour post breakfast | 
| Carbohydrate Oxidation | Investigators will be collecting expired air into Douglas bags, and measuring the VO2 and VCO2 concentration to calculate carbohydrate oxidation. | 0 hour (pre breakfast), 1 hour, 2 hour, 3 hour post breakfast | 
| Fat Oxidation | Investigators will be collecting expired air into Douglas bags, and measuring the VO2 and VCO2 concentration to calculate fat oxidation. | 0 hour (pre breakfast), 1 hour, 2 hour, 3 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chrononutrition, Time-Restricted Eating, Energy Balance, Glycaemic Control