Effect of Exercise on Appetite in Response to Meals

Study Overview
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Brief Summary
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This clinical trial's primary aim is to investigate the acute effect of two exercise bouts (short [10 minutes] and long [30 minutes]) on appetite and appetite-regulatory hormone responses to a standard meal test. The secondary aim is to investigate when the changes in appetite and appetite-regulatory hormones occur during exercise. As an exploratory aim, the researchers will test if the two exercise bouts influence ad libitum energy intake in the periods after the standard meal test. The researchers will compare three groups (control, short exercise, and prolonged exercise) to see if the exercise bouts affect appetite, appetite-regulatory hormones, and energy intake in healthy men.

Detailed Description
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Study Design Screening visit Before conducting the main experiments, the participants will attend a screening visit where consent will be obtained, and they will complete questionnaires to assess health, food preferences, and physical activity. The researchers will then measure the participants' height, weight, waist circumference, and body composition. After the researchers confirm the eligibility criteria, participants will take part in two treadmill tests to establish maximum oxygen uptake test (V̇O2 max) (Broom et al. 2017). Experimental design After the screening visit, the participants will complete three main experiments (control, short high-intensity exercise, and prolonged high-intensity exercise) in a counter-balanced design. All experiments began at  0930, following an overnight fast of at least 10 hours. Participants will consume a prescribed meal in the evening before each main experiment. Following this meal, participants are only allowed to drink water until the start of the main experiments. At the beginning of the exercise conditions, participants will run on the treadmill for 10 minutes (short) or 30 minutes (prolonged) at a speed estimated to elicit a 75% V̇O2 peak, followed by rest in the laboratory. In the control condition, the researchers will follow the same protocols except that the participants will not perform any exercise. The participants will have a standardized meal after exercise and then an ad libitum buffet meal afterward. During each experiment, the researchers will assess appetite ratings using 100 mm visual analog scales (Flint et al. 2000). The researchers will also collect blood samples to examine ghrelin, peptide YY, glucagon-like peptide 1, and possibly other blood-borne measures.

Official Title
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Acute Effect of Exercise on Post-meal Appetite, Appetite-Regulatory Hormones, and Energy Intake in Healthy Men

Conditions
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Healthy

Intervention / Treatment
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* Other: Bouts of Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males aged 18 years or older. Have stable body mass for at least six months (within ±2 kg). Exclusion Criteria: Females People who are younger than 18 or older than 65 years old. Have food allergies. Have significant contraindications to exercise (e.g., an injury that would inhibit running). Smoking. Suffering from metabolic health issues, e.g., history of diabetes, cardiovascular disease, or eating disorders.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>The participants will not perform any exercise. | |
| Experimental: Short Exercise<br>The participants will run on the treadmill for 10 minutes. | Other: Bouts of Exercise<br>* The participants will run on the treadmill for 10 minutes (short) or 30 minutes (prolonged).<br>|
| Experimental: Prolonged Exercise<br>The participants will run on the treadmill for 30 minutes. | Other: Bouts of Exercise<br>* The participants will run on the treadmill for 10 minutes (short) or 30 minutes (prolonged).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Peptide-YY (PYY) | Blood samples will be drawn at different time points during the trial to measure the change in PYY blood levels. Area under the plasma concentration versus time curve (AUC) of PYY will be calculated using the trapezoidal rule. | At 0 (baseline), 0.167, 0.5, 1, 1.5, 2, 3, and 4 hours | 
| Change in Ghrelin | Blood samples will be drawn at different time points during the trial to measure the change in ghrelin blood levels. Area under the plasma concentration versus time curve (AUC) of ghrelin will be calculated using the trapezoidal rule. | At 0 (baseline), 0.167, 0.5, 1, 1.5, 2, 3, and 4 hours | 
| Change in Glucagon-Like Peptide-1 (GLP-1) | Blood samples will be drawn at different time points during the trial to measure the change in GLP-1 blood levels. Area under the plasma concentration versus time curve (AUC) of GLP-1 will be calculated using the trapezoidal rule. | At 0 (baseline), 0.167, 0.5, 1, 1.5, 2, 3, and 4 hours | 
| Change in subjective appetite sensations | The subjective appetite sensations will be assessed using 100 mm visual analog scales (VAS) to measure appetite sensations (hunger, satiety, fullness, prospective food consumption, and desire to eat). The VAS are 100 mm long, with words anchored at each end expressing the most positive and negative ratings. Scores for each appetite construct range from 0-100. | At 0 (baseline), 0.167, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 5.5, and 6 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Energy Intake | To determine the amount of each food item consumed, we will measure the difference in weight between before and after the meal. We will use manufacturer details to determine energy consumption. | At 5 hours | 
| Macro-nutrient Intake | To determine the amount of each food item consumed, we will measure the difference in weight between before and after the meal. We will use manufacturer details to determine macronutrient consumption | At 5 hours |