CompletedInterventional

Assessing the metabolic effect of sustainable proteins

This study aims to understand how our bodies process new, sustainable protein sources like fermented and plant-based foods, compared to red meat. Many people are choosing these options because of environmental concerns and health benefits like lower cholesterol and better blood sugar. We don't fully understand how our bodies react to these new proteins. By taking part, healthy volunteers will help us learn how these foods are digested and used by the body. This research could help in developing healthier and more sustainable food options for everyone in the future.

At a glance

Status

Completed

Sponsor

Imperial College London

Enrolment target

Start

01 Dec 2025

Estimated completion

01 Jun 2026

Prevention of metabolic disease in currently healthy volunteers

What is this study about?

This research is looking into how our bodies handle different types of protein. We know that eating a lot of red meat might not be the best for our health or the planet. Because of this, more and more people are trying new, eco-friendly protein sources, like those made from plants or fermented foods. These alternatives might even have health benefits, like helping to keep cholesterol down and blood sugar stable, which could protect against long-term health problems.

However, we don't yet fully understand how our bodies break down and use these newer protein foods compared to traditional red meat. This study aims to fill that gap. We want to see how these different protein meals affect your body, from how they are digested to how they influence your metabolism – that's how your body turns food into energy.

By comparing a fermented protein product, its unfermented version, and beef, we hope to learn more about the specific ways each affects a healthy person's body. The information we gather could be really important for creating healthier and more environmentally friendly food choices for the future.

Key takeaways

Help scientists understand how new, eco-friendly proteins are digested.
Your participation could help develop healthier and more sustainable foods.
Involves three overnight stays at a research facility in London.
You will try different protein meals, including beef and new alternatives.
Includes health checks, blood tests, and recording your diet.
Study runs from November 2025 to June 2026.

Who may be eligible?

You might be able to take part if you are generally healthy, aged between 18 and 65, and have a body mass index (BMI) within the healthy to overweight range (18.5 to 29.9).

However, there are several reasons why you wouldn't be able to join. For example, you can't be pregnant or breastfeeding, a smoker, or have certain health conditions like heart disease, kidney failure, or cancer. We also can't include people who have had a big change in their weight recently, have certain food allergies, or have used specific medications like antibiotics in the last three months. Vegetarians and vegans are also not suitable for this particular study.

Before you start, we'll do a health check-up, including a blood test, to make sure it's safe for you to participate and that you meet all the study's requirements.

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 65 years old?
Do you have a BMI between 18.5 and 29.9?
Are you free from conditions like heart disease, kidney failure, or cancer?
Are you not pregnant or breastfeeding?
Have you avoided antibiotics in the last 3 months?
Are you a non-smoker and do not drink more than 14 units of alcohol per week?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll first visit the NIHR Imperial Clinical Research Facility in London for a screening appointment. This is where we’ll check if you're suitable for the study, answer any questions, and take some measurements like your height, weight, and blood pressure, along with some blood tests. If you're a woman of childbearing age, we'll also do a pregnancy test. You'll complete a questionnaire about your health and medical history.

If you're eligible, you'll have three separate study visits, each lasting about 25 hours, meaning you'll stay overnight at the facility. For four days before each visit, you'll use an online app called Libro to record everything you eat and drink. The day before each visit, you'll also collect a stool sample at home and bring it with you. We'll ask you to avoid alcohol and intense exercise the day before each visit.

During each of the three main visits, you'll be given a different meal to eat: one will be a fermented protein product, one its unfermented version, and one beef. We'll give you an evening meal and a snack on the first day. The next morning, we'll take your weight and blood pressure, and place a small, flexible tube (cannula) in your arm so we can take small blood samples easily throughout the day. You'll also provide urine samples, blow into a device for breath tests, and complete short questionnaires about your appetite. You’ll have breakfast, lunch, and a final meal where you eat until you’re comfortably full. After this final meal, the tube will be removed and you will be free to leave. You can continue your usual diet outside of these study visits. In total, the study will run from November 2025 to June 2026, and your involvement will be spread across these months.

Potential risks and benefits

You won't directly benefit from taking part in this study. However, the information we gather will help us better understand how sustainable proteins are digested and used by the human body. This knowledge is important for developing healthier, more eco-friendly food options in the future. The main risks involve discomfort from blood tests, such as bruising or a small chance of infection; these procedures will be performed by trained staff in a clean environment to keep risks very low. All the meals provided are safe to eat. You have the right to withdraw from the study at any time without giving a reason.

Locations (1)

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

NIHR Imperial Clinical Research Facility
City only
London, England

Common questions

What is a 'sustainable protein'?

Sustainable proteins are food sources like certain plant-based options or fermented products that have less impact on the environment to produce compared to traditional meat.

What is a 'metabolic effect'?

A metabolic effect means how a food influences the way your body turns food into energy and manages things like blood sugar and fats.

Will I have to eat specific foods outside the study visits?

No, outside of your study visits, you can continue to eat your usual diet. You'll only need to record what you eat for a few days before each visit.

What is a cannula?

A cannula is a small, soft plastic tube placed in your arm, often used in hospitals. It lets us take blood samples easily without needing to poke you with a needle each time.

Who is paying for this study?

The study is being funded by The Bezos Centre for Sustainable Proteins based in the UK.

How to find out more

Jennifer Pugh

jennifer.pugh3@nhs.net - Official trial record

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