Not yet recruitingNAINTERVENTIONAL

Impact of Diet-induced Change in Energy Balance on Metabolism in Endurance Athletes

This study aims to understand how different diets affect athletes' bodies, specifically focusing on how they use energy. We know athletes burn a lot of energy, and not eating enough can cause problems. Some research suggests that even active people's bodies try to save energy by slowing down other processes. This study will involve male and female athletes who train regularly. They will follow two different diets for a short time: one where they eat less energy than they burn, and one where they eat a bit more. Researchers will measure how their bodies use energy, their health, and their performance to see what impact these diets have. This helps us understand if being very active changes how the body manages its energy, and if not eating enough affects health and performance.

At a glance

Status

Not yet recruiting

Phase

Sponsor

University of Bath

Enrolment target

Start

01 Aug 2025

Estimated completion

01 May 2027

Energy Balance Energy Deficit Low Energy Availability Relative Energy Deficiency in Sport

What is this study about?

Imagine your body as a car. To run well, it needs fuel. For athletes, who are like high-performance cars, they need a lot of fuel because they burn so much energy with their intense training. This study wants to understand what happens when athletes don't eat enough fuel to match the energy they're using, a situation called 'energy deficit'.

When people don't eat enough to cover their activity, their bodies might try to save energy. This could mean slowing down certain body functions, not just for highly active people but also for those who exercise moderately. Think of it like your body dimming the lights in other rooms to save electricity when you're running a powerful appliance. While this might seem helpful to save energy for exercise, it could also affect important things like your immune system, which helps you fight off sickness, or your body's ability to recover.

This research is important because most studies on energy deficit haven't focused on people who are as active as endurance athletes. Athletes have much higher energy demands, so these energy-saving changes might be more noticeable or have different consequences for them. We also don't fully understand how quickly these changes in energy use happen or how they affect tiny parts of cells, like those involved in muscle function. By helping us understand this, the study could give us new insights into how to keep athletes healthy and performing at their best.

Key takeaways

Aims to understand diet's impact on athletes' energy use.
Compares effects of eating too little vs. enough food for athletes.
Involves tracking energy balance and health in active individuals.
Could help develop better health and performance advice for athletes.
Participants will follow specific diets for two 7-day periods.

Who may be eligible?

This study is looking for male and female athletes who are 18 to 49 years old. You should regularly train for endurance sports, meaning you do more than 7 hours of endurance training at least 5 days a week. For example, if you run, cycle, or swim long distances often, you might be a good fit.

However, some conditions would mean you can't take part. These include having certain health issues like diabetes, an active eating disorder, or a chronic illness that's currently causing problems. If you have an injury that stops you from high-level training, or if you're currently pregnant, breastfeeding, or have been breastfeeding in the last 6 months, you wouldn't be able to join. Also, if you're taking medications that affect how your body uses energy (like statins or thyroid hormones) or if you've recently donated blood, you might not be eligible. The researchers will check these things carefully.

The main idea is to ensure participants are healthy endurance athletes who don't have existing conditions that could interfere with the study's results or put their health at risk during the trial.

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 between 18 and 49 years old?
Do you do more than 7 hours of endurance training, at least 5 days a week?
Do you NOT have diabetes or an active eating disorder?
Are you NOT pregnant, breastfeeding, or recently breastfeeding (within 6 months)?
Are you comfortable with consuming study-provided food?
Are you able to undertake a treadmill running assessment?

Answer every question to see your result.

What does participation involve?

If you take part in this study, you will follow a specific diet for two separate periods, each lasting 7 days. During one period, your diet will provide less energy than your body needs (an 'energy deficit'). During the other period, you'll eat a bit more (an 'energy surplus'). These two periods will be chosen randomly, so you won't know which one you're doing first.

You will continue your usual training and daily life during these periods. The researchers will provide all your food to make sure your diet is carefully controlled. Throughout the study, various measurements will be taken to see how your body uses energy, how your metabolism is working, and how your health and performance are affected. These measurements might include things like your resting metabolism, how much energy you burn during exercise, and other health markers. The exact number of visits and specific tests would be explained in more detail if you are interested in joining.

Potential risks and benefits

Taking part in this study could help us better understand how diet and energy balance affect athletes' health and performance. This knowledge could eventually lead to better guidance for athletes. During the study, you will be in an 'energy deficit' for one week, which means eating less than your body needs. While your diet will be supervised by nutrition experts, some people might feel tired, hungry, or notice a slight dip in energy or performance during this period. Your health will be monitored, but there could be minor discomforts or temporary effects. You are free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (1)

University of Bath
Verified postcode
Bath, United Kingdom

Common questions

What is 'energy balance'?

Energy balance is simply the relationship between the amount of energy (calories) you eat and the amount of energy your body uses.

What does 'energy deficit' mean?

It means you're eating fewer calories than your body is burning, so your body has less energy available than it needs.

Will I have to stop training if I join?

No, you will continue your normal training during the study periods.

Why is the diet controlled?

The diet is controlled because the study needs to precisely adjust the amount of energy you take in to see its specific effects.

Who is funding this research?

The information provided does not specify the funding source. You can ask the research team if you are interested in participating.

How to find out more

Joshua J Bakker-Dyos, BSc(Hons) MBChB

jbd28@bath.ac.uk +447740191473 Official trial record

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