RecruitingNAINTERVENTIONAL

Effect of Exercise on Appetite in Response to Meals During Energy Restriction

This study is investigating how exercise impacts appetite and the hormones that control hunger when people are eating very few calories. Researchers want to understand if a 30-minute exercise session can change how hungry healthy men feel and how much they eat after a period of low-calorie intake. They will compare three groups: one eating normally (control), one eating very few calories, and another eating very few calories but also exercising. This will help them see if exercise makes a difference to appetite and overall food intake following a low-calorie diet.

At a glance

Status

Recruiting

Phase

Sponsor

University of Glasgow

Enrolment target

Start

30 Jul 2025

Estimated completion

30 Apr 2028

Healthy

What is this study about?

Imagine you're trying to eat less to improve your health. Sometimes, when you cut down on food, you might feel really hungry. This study wants to see if adding some exercise can help manage that hunger. Researchers are looking at healthy men and comparing what happens to their appetite and certain hunger-related hormones when they reduce their food intake a lot, with or without a short exercise session.

The main goal is to find out if exercising for 30 minutes can affect how hungry people feel and how much they end up eating later, especially when they're on a very low-calorie diet. The study will also measure hormones in the blood that play a part in telling your body whether you're full or hungry.

They plan to do this by asking participants to come in for three different 24-hour visits. During each visit, participants will either eat their normal amount of food, eat a very small amount of food without exercise, or eat a very small amount of food with a 30-minute run on a treadmill. By comparing these different situations, the researchers hope to learn more about how exercise might help control appetite when someone is eating fewer calories.

Key takeaways

Study examines how exercise affects hunger while on a low-calorie diet.
Compares appetite in healthy men during normal eating, low-calorie, and low-calorie with exercise.
Involves three 24-hour visits after initial health checks and fitness tests.
Participants will eat controlled meals, give blood samples, and rate hunger levels.
Aims to understand if exercise helps manage appetite when eating less.

Who may be eligible?

This study is specifically looking for healthy male volunteers who are at least 18 years old. You should have a stable body weight, meaning your weight hasn't changed much (up or down by more than about 2 kg) in the last six months.

There are several reasons why you might not be able to join. For example, if you are female, under 18, or over 65, you won't be eligible. You also can't be on any special diets, like trying to lose weight or being a vegetarian or vegan. If you have any food allergies that affect the study meals, or if you have an injury that stops you from running, you also won't be able to take part.

Finally, if you smoke, take regular medications, or have any health conditions like diabetes, heart problems, eating disorders, or mental health issues, you won't be able to join the study. The researchers need participants to be very healthy and not have other factors that might affect the results.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you Male?
Are you between 18 and 65 years old?
Has your weight been stable for the last 6 months (no big changes)?
Do you avoid special diets (like vegetarian, vegan, or weight loss diets)?
Do you have good overall health, without serious medical conditions?
Are you able to run on a treadmill for 30 minutes without injury?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll first have a screening visit. This involves checking your general health, discussing your food preferences, and measuring things like your height, weight, and body composition. You'll also do two treadmill tests to work out your fitness level.

After screening, you'll come in for three main visits, each lasting 24 hours. These visits will be spread out over time, and the order will vary for different people. For each visit, you'll need to fast (only drink water) for at least 10 hours before coming in, following a special meal the evening before. During these 24-hour visits, you'll either rest in the lab, exercise on a treadmill for 30 minutes, or simply rest. Your meals will be carefully controlled – either full meals or very small ones, depending on the visit type. You'll also have blood samples taken to measure certain hormones and you'll be asked to rate your hunger using a simple scale. At the very end of each 24-hour visit, you'll be offered a buffet meal and can eat as much as you like. The total duration of your involvement will depend on how quickly you complete the three main visits.

Potential risks and benefits

Participating in research studies like this helps us learn more about how our bodies work, which could eventually lead to better health advice for everyone. While there's no direct personal benefit from this study, you'll be contributing important information to science. Potential risks might include the slight discomfort of giving blood samples, or feeling hungry during the low-calorie phases. The exercise component involves running on a treadmill, which carries a small risk, but you will have been screened for your fitness. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

New Lister Building, Glasgow Royal Infirmary
Verified postcode
Glasgow, United Kingdom· Recruiting

Common questions

What kind of exercise will I do?

You'll run on a treadmill for 30 minutes at a moderate to challenging pace, which will be set based on your fitness test results.

Will I have to stay overnight?

No, each of the three main study visits lasts for 24 hours but it's not an overnight stay in the traditional sense, you will be in the lab for the day.

Will I feel very hungry during the study?

During parts of the study, your food intake will be very low, so it's possible you might feel hungry. This is part of what the researchers are studying.

What happens after the 24-hour visits?

At the end of each 24-hour visit, you'll be offered a buffet meal where you can eat as much as you like, and then you'll return home.

Will I know my results?

The study usually doesn't provide individual results, but the overall findings will be published and shared with the scientific community.

How to find out more

Sultan Alenezi, MSc

a.sultan-kheneisr-w.1@research.gla.ac.uk +44 778 653 0734 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.