CompletedInterventional

Investigating the effect of time-restricted eating on sperm quality

This study is investigating whether time-restricted eating (TRE) can improve the quality of sperm in men. TRE means you only eat within a certain window, like 11 am to 7 pm, each day. Researchers are interested because male fertility has been declining and TRE has shown other health benefits. Participants aged 18-44 who are already having fertility checks will have their sperm tested, follow the TRE plan for three months, and then have their sperm tested again. The goal is to see if this eating pattern can lead to healthier sperm and potentially offer a new way to support male fertility.

At a glance

Status

Completed

Sponsor

Bristol Centre for Reproductive Medicine Limited

Enrolment target

Start

23 Feb 2024

Estimated completion

14 Nov 2024

Sperm quality

What is this study about?

Over the last 50 years, there has been a noticeable decline in male fertility around the world, but there haven't been many new treatments or much research into why this is happening. This study aims to explore a promising new area: how our eating patterns might affect sperm health. Researchers are focusing on something called time-restricted eating (TRE).

TRE is a way of eating where you limit all your daily meals and snacks to a specific window, usually 8-10 hours, and only drink water, black tea, or coffee during the rest of the day. For example, you might eat only between 11 am and 7 pm. This way of eating has been linked to several positive health changes, including helping with weight loss, improving how the body handles sugar, balancing hormones, and making the gut healthier. Because TRE seems to have such a positive impact on overall health, the researchers wonder if it could also boost sperm production and quality, which hasn't been studied before.

By understanding if TRE can improve sperm quality, this research could be a valuable step in finding new ways to help men with fertility issues. If the study shows positive results, it could provide a simple, healthy lifestyle change that might help improve male fertility rates.

Key takeaways

This study explores if eating during an 8-hour window (11 am-7 pm) can improve male sperm quality.
It aims to find new, natural ways to support male fertility.
Participants will have sperm tests before and after three months of time-restricted eating.
Free sperm test results, worth over £500, are a benefit of joining.
You must be a non-smoking male, aged 18-44, with a healthy BMI and no diabetes or eating disorders.
You can leave the study at any time if you wish.

Who may be eligible?

This study is looking for men aged between 18 and 44 years old who are currently having fertility tests at clinics. To take part, you must have a healthy weight (not underweight, with a Body Mass Index of 18.5 or more) and not be a smoker. You also need to have sperm that can be found in your ejaculate.

There are a few reasons why you might not be able to join. For example, if you have diabetes, have had an eating disorder in the past, or if you're taking medication that needs to be taken with food, you wouldn't be suitable. Also, if you've had weight loss surgery in the past, you wouldn't be able to participate. The study is also not for men aged 45 or older.

Basically, the team wants to make sure participants are generally healthy and that any changes seen are likely due to the eating plan, rather than other health conditions or medications.

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 a male aged between 18 and 44?
Do you get fertility checks at a clinic?
Do you not smoke?
Do you have a healthy weight (BMI 18.5 or more)?
Do you not have diabetes?
Have you never had an eating disorder?

Answer every question to see your result.

What does participation involve?

If you decide to take part, your journey will start with a visit to the clinic. First, you'll have a sample of your sperm tested. This helps the team understand things like the amount of sperm you have, how well they move, and what they look like, along with a test for something called oxidative stress in the semen.

After these initial tests, you'll be asked to follow the time-restricted eating (TRE) plan for three months. This means you'll only eat between 11 am and 7 pm each day, and for the rest of the day, you'll only drink water, black tea, or black coffee. It's really important to stick to this schedule as closely as possible, and you'll be asked to record your eating times. After three months, you'll return to the clinic to provide another sperm sample so the team can see if the TRE plan has made any changes. Some of your sperm samples will also be frozen and carefully examined for other changes, like different sugars and proteins within them. The study is expected to run from November 2022 to May 2025.

Potential risks and benefits

Taking part in this study offers some clear benefits. You'll receive the results of all your advanced sperm tests, which would normally cost over £500, completely free of charge. You can discuss these results with a fertility expert. Time-restricted eating itself has also been shown to have various health advantages for your physical health and general well-being. Beyond your personal gain, your participation will help doctors learn more about how diet and lifestyle can affect male fertility. If successful, this research could lead to new, simple ways to help men improve their fertility. However, sticking to a specific eating window for three months can be challenging and might feel a bit restrictive at times. While support will be available, there's also a chance that time-restricted eating might not improve sperm quality, or it could even temporarily affect it negatively. The research team will be watching closely, and if any significant decline in sperm health is noticed, the study will be stopped early. You can also leave the study at any time.

Locations (3)

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

Bristol Centre for Reproductive Medicine (Almondsbury)
City only
Bristol, United Kingdom
North Bristol NHS Trust
City only
Bristol, United Kingdom
University Hospitals Bristol and Weston NHS Foundation Trust
City only
Bristol, United Kingdom

Common questions

What is time-restricted eating (TRE)?

TRE means you only eat your meals and snacks within a set timeframe each day, often 8-10 hours, and stick to water or plain drinks outside of that window. For this study, it's 11 am to 7 pm.

What will happen during my clinic visits?

You’ll provide a sperm sample at the beginning of the study and another one after three months of time-restricted eating. These samples will be analysed to check sperm quality.

Will I have to pay to take part?

No, you will not be paid for taking part, but you will receive valuable sperm test results for free that would normally cost over £500.

Can I stop participating if I change my mind?

Yes, you are free to withdraw from the study at any time without giving a reason.

What if time-restricted eating makes my sperm quality worse?

The research team will be carefully monitoring all participants, and if any significant drop in sperm quality is noticed, the study will be stopped early. Any changes are expected to be temporary.

How to find out more

Jennifer Nisbett

jennifer.nisbett@bcrm.clinic +44 (0)117 2591159 Official trial record

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