RecruitingInterventional

The Fish and Meat study

The 'Fish and Meat Study' is investigating how different diets — meat-based, fish-based, or plant-based — impact heart health. Researchers know that eating fish can help protect your heart, but it can also raise levels of a chemical sometimes linked to unhealthy red meat diets. This study aims to clarify if this chemical is still a concern for fish-eaters, or if fish remains a healthy choice for heart health compared to meat. It involves overweight adults aged 30-65, who will try different diets over 14 weeks. Regular health checks will help researchers understand the diets' effects.

At a glance

Status

Recruiting

Sponsor

University of Aberdeen

Enrolment target

Start

01 Apr 2025

Estimated completion

31 Mar 2027

Cardiovascular disease

What is this study about?

You might have heard that eating fish is good for your heart, and that too much red meat might not be. This study, called ‘The Fish and Meat Study’, wants to explore this further. Researchers are specifically looking into how different types of diets – one that includes meat, one that is focused on fish, and one that is vegetarian – affect your heart health.

They are interested in a particular chemical that the body produces. Eating fish can increase levels of this chemical, but it has also been linked to diets high in red meat, which itself has been connected to heart problems. The main goal of this study is to figure out if this chemical is something to worry about when you’re eating a lot of fish, or if eating fish is still a much healthier option for your heart compared to a meat-heavy diet.

By comparing what happens in people who eat these different diets, the study aims to give clearer answers about the best dietary choices to protect your heart. The findings could help us understand which foods truly promote a healthy heart and reduce the risk of heart disease for many people.

Key takeaways

Compares meat, fish, and plant-based diets for heart health.
Aims to understand how a specific chemical affects heart health with different diets.
Involves 14 weeks of dietary changes and regular health check-ups.
Open to overweight adults (30-65) with slightly elevated blood fats, sugar, or pressure, not on medication.
Could help future recommendations for preventing heart disease.
You'll get personal health feedback at the end of the study.

Who may be eligible?

This study is looking for healthy men and women between the ages of 30 and 65. You should be a bit overweight, meaning your Body Mass Index (BMI) is between 25 and 29.9. You also need to have slightly higher-than-normal levels of fats or sugar in your blood, or slightly elevated blood pressure, but importantly, you shouldn't be taking any medication for these conditions already.

There are also some reasons why you might not be able to join. For example, if you have diabetes, heart disease, or very high blood pressure that needs medication, this study isn't suitable. You also can't take part if you're pregnant, have certain bowel conditions, or drink more than 14 units of alcohol a week. The study also isn't for people who are very underweight or very overweight (BMI over 29.9), or if you already take regular medication or supplements that could affect the study 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 between 30 and 65 years old?
Is your BMI between 25 and 29.9 (overweight, but not very overweight)?
Do you have slightly high blood fats, blood sugar, or blood pressure, but aren't on medication for them?
Do you not have diabetes, heart disease, or very high blood pressure?
Are you able to regularly visit The Rowett Institute in Aberdeen?
Are you willing to follow specific diets and undergo regular health checks?

Answer every question to see your result.

What does participation involve?

If you decide to take part, your journey will start with a health screening at The Rowett Institute in Aberdeen. This check-up ensures the study is safe and right for you. It will involve reviewing your health history, measuring your height, weight, waist, and blood pressure, and a quick finger-prick blood test to check your blood fats and sugar. They'll also painlessly measure how much energy your body uses at rest by looking at your breathing. You'll complete a four-day food diary before your next visit.

The main part of the study lasts 14 weeks and involves 7 more visits to the Institute. You'll be randomly put into one of three diet groups: a meat-based diet, a fish-based diet, or a plant-based diet. For the first week, everyone eats a control diet, similar to what many people in the UK eat. Then, you'll follow your assigned diet for 6 weeks. After that, you'll go back to the control diet for one week, before switching to a different study diet for another 6 weeks. During these weeks, you'll have various measurements taken, including urine and stool samples, blood tests after not eating for a while (fasted blood tests), 24-hour blood pressure monitoring, and weight checks. Your blood vessel stiffness will be checked with a painless ultrasound, and body fat with a special Bod Pod machine. A small sensor on your skin will also continuously track your sugar levels throughout the day and after drinking a sugary solution.

Potential risks and benefits

The dietary changes in this study are generally small, so major side effects are not expected. However, some people might notice changes in their bowel movements, such as different stool consistency, bloating, or constipation. If these occur, the study team will offer advice to help. Blood tests might cause a little discomfort or bruising, and some people might feel a bit light-headed. You can stop participating at any time if you wish. While you might not directly benefit from taking part, the information gathered could help many others by improving our understanding of how diet affects heart health. After the study, you'll receive a confidential report with your blood pressure, weight, blood sugar, and cholesterol results, and your GP will also be informed of these findings.

Locations (1)

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

The Rowett Institute
City only
Aberdeen, United Kingdom

Common questions

What is the main purpose of this study?

The study aims to understand how diets focusing on meat, fish, or plants affect heart health, particularly regarding a chemical linked to both fish and red meat.

How long will I need to be involved?

The study intervention itself lasts 14 weeks, with an initial screening and then 7 additional visits to The Rowett Institute.

Will I get to choose my diet group?

No, you will be randomly assigned to one of the three diet groups (meat, fish, or plant-based) to ensure fair comparison between the groups.

What kind of tests will I have?

You'll have various health checks, including blood tests, urine and stool samples, blood pressure monitoring, body fat measurements, and a sensor to track your sugar levels.

Will I find out my own health results?

Yes, you will receive a confidential personal feedback report at the end of the study, including your blood pressure, weight, blood glucose, and cholesterol results.

How to find out more

Frank Thies

f.thies@abdn.ac.uk +44 (0)1224437954 Official trial record

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