RecruitingNAINTERVENTIONAL

Blood Lipid Responses to Diet Macronutrients

This study explores how the balance of carbs and fats in your diet affects your blood fats and liver health. We know that the types of food we eat influence our risk of conditions like heart disease or diabetes. However, it's not clear what the ideal mix of carbs, fats, and proteins is, especially when you're not trying to gain or lose weight. Researchers will ask healthy adults to follow either a high-carb, low-fat diet or a low-carb, high-fat diet for nearly a month. They'll examine how these diets impact fat levels in the blood and how the liver works. The study will also look at how your individual genes might influence your body's response to these different eating plans.

At a glance

Status

Recruiting

Phase

Sponsor

University of Oxford

Enrolment target

Start

15 Feb 2023

Estimated completion

01 Jan 2028

Nutritional and Metabolic Diseases

What is this study about?

This study is all about understanding how the main types of food we eat – carbohydrates (like bread, pasta, sugar) and fats (like those in oils, butter, and some meats) – affect our bodies, especially our blood fats and liver. We know that what we eat has a huge impact on our health and can influence our risk of developing conditions like heart disease or diabetes.

Doctors often recommend changes to diet and lifestyle to help reduce the risk of these health problems. However, there isn't a single diet that works best for everyone, and experts debate the ideal balance of carbs, fats, and proteins, particularly when a person isn't trying to lose or gain weight. For example, if you eat less fat, you'll naturally eat more carbs, and vice versa. This study wants to find out what this shift in food types means for your body's health.

The main goal is to see how different amounts of carbs and fats affect the fat levels in your blood (both after not eating for a while and after a meal), the amount of fat in your liver, and how your liver and heart work. The researchers also want to understand if your personal genes influence how your body reacts to these dietary changes. This could help tailor dietary advice more specifically to individuals in the future.

Key takeaways

This study investigates how different levels of carbs and fats in your diet affect your blood fats and liver.
It aims to find out the best dietary balance to prevent heart disease and other metabolic conditions.
You'll follow a specific diet (either high-carb/low-fat or low-carb/high-fat) for about four weeks.
Researchers will also look at how your genes might influence your body's response to the diet.
Participation involves health checks before and after the diet period.
This research could help develop more personalised dietary advice in the future.

Who may be eligible?

To join this study, you need to be a healthy man or woman between 18 and 65 years old. Your body mass index (BMI), which is a measure of your weight compared to your height, should be between 19 and 35. You also need to have been at a steady weight for the past three months.

There are certain reasons you wouldn't be able to join. For example, if you have any medical condition that affects your liver, fat tissue, or heart, or if you're taking medication for such a condition. You also can't participate if you've recently had a significant blood donation or weight change (more than 5% gain or loss in the last three months). If you smoke, drink a lot of alcohol, are pregnant or breastfeeding, or have severe claustrophobia, you wouldn't be eligible.

Also, if you've been on a special diet with very different amounts of carbs and fats in the last three months (like a very high-fat or very low-carb diet), or if you have a history of allergies to a substance called albumin, you won't be able to take part.

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?
Is your BMI (Body Mass Index) between 19 and 35?
Have you been at a stable weight for the last 3 months?
Do you have any medical conditions or take medicines that affect your liver, fat, or heart?
Have you changed your diet significantly (like a very low-carb or high-fat diet) in the last 3 months?
Are you pregnant or breastfeeding, or do you have severe claustrophobia?

Answer every question to see your result.

What does participation involve?

If you join this study, you'll be one of 60 healthy volunteers. You'll be randomly assigned to one of two groups: either a diet that is low in carbohydrates and high in fats, or a diet that is high in carbohydrates and low in fats. You'll follow this specific diet for up to 28 days (about four weeks).

The food provided during the study will be designed to give you the right amount of energy, so you won't be expected to gain or lose weight. Before and after following your assigned diet, you will have several detailed health checks. These checks will measure how your body processes fats, how your liver is working, and possibly how your heart is functioning. These tests help the researchers understand the effects of the different diets on your body.

Potential risks and benefits

Taking part in a study like this helps advance medical knowledge, which could eventually benefit many people by improving dietary advice. While there's no direct personal benefit promised, you might gain a better understanding of your own body. Potential risks could include minor discomfort from blood tests or other assessments, or perhaps finding the dietary changes challenging. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (2)

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

Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
Verified postcode
Oxford, United Kingdom· Recruiting
Oxford Centre for Diabetes, Endocrinology and Metabolism
Verified postcode
Oxford, United Kingdom· Recruiting

Common questions

What is a 'macronutrient'?

Macronutrients are the main types of food your body needs in large amounts: carbohydrates, fats, and proteins. They provide energy and are essential for health.

What kind of medical conditions are they looking at?

This study is focused on conditions like heart disease, type 2 diabetes, and fatty liver disease, which are often linked to how our bodies handle food.

Will I gain or lose weight on this diet?

The diets in this study are carefully planned to match your energy needs, so you are not expected to gain or lose weight.

What does 'genotyping' mean?

Genotyping means looking at your genes (your body's instruction manual) to see if certain genetic differences might affect how your body reacts to different diets.

How long will I be on the special diet?

You will follow either a low-carb, high-fat diet or a high-carb, low-fat diet for up to 28 days (about four weeks).

How to find out more

David J Dearlove

david.dearlove@ocdem.ox.ac.uk 07739460623 Official trial record

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