RecruitingInterventional

Quantifying and modifying ultra-processed food intake in the management of functional dyspepsia

This study, run by University College London, is exploring a link between highly processed foods (called UPFs) and persistent indigestion (functional dyspepsia). Functional dyspepsia causes tummy discomfort, bloating, and feeling full quickly, and current medicines don't always fully help. Researchers want to find out if people with this condition tend to eat a lot of UPFs. If so, they will then test whether switching to a diet with more natural, minimally processed foods can improve symptoms. The study aims to support participants in making healthy, long-term changes, tracking their symptoms and quality of life over three months. This could lead to new dietary advice for managing functional dyspepsia.

At a glance

Status

Recruiting

Sponsor

University College London

Enrolment target

126

Start

01 Aug 2025

Estimated completion

01 Jul 2026

Functional dyspepsia

What is this study about?

This research study is looking into a common tummy problem called functional dyspepsia. If you have this, you might often feel pain or burning in your upper stomach, get bloated, or feel full very quickly even after a small meal. These symptoms can be really disruptive to daily life. While there are medicines for it, they don't always work perfectly for everyone, and advice on special diets for this condition can be confusing.

Recently, there's been a lot of talk about 'ultra-processed foods' (UPFs) and how they might affect our health, including our digestion. UPFs are foods that have been changed a lot during their making and often contain extra ingredients like preservatives, flavourings, and colours. This study first wants to see if people with functional dyspepsia tend to eat a lot of these UPFs. This information is important because it could help us understand if there's a link between these foods and the condition.

For some people in the study, especially those who regularly eat a lot of UPFs, the researchers will then test if switching to a diet based on 'minimally processed foods' can help. This would involve eating more natural, whole foods. Along with diet changes, participants will get support to build healthy habits that they can keep up in the long run. The researchers will follow people for three months to see if their symptoms improve, if their quality of life gets better, and if other health markers change. The ultimate goal is to discover if reducing UPF intake could offer a new and effective way to help people manage their functional dyspepsia.

Key takeaways

Exploring if highly processed foods are linked to chronic indigestion (functional dyspepsia).
May offer a new way to manage symptoms by changing diet.
Participation could involve tracking your current eating habits.
Some participants might be supported to switch to a healthier, minimally processed food diet.
The study helps improve understanding of functional dyspepsia, which could benefit future patients.

Who may be eligible?

To take part in this study, you need to be an adult between the ages of 18 and 64 who has been diagnosed with functional dyspepsia. This diagnosis means you've had ongoing stomach discomfort like pain, burning, or feeling full quickly for at least 8 weeks, and doctors haven't found another clear reason for your symptoms after investigations, such as an endoscopy. You also need to be able to read and write in English and be happy to give your written consent to join.

There are also some extra requirements if you are invited to join the part of the study that involves changing your diet. You would need to typically eat a lot of ultra-processed foods. If you are a woman who could become pregnant, you'd need to confirm you're not pregnant and agree to use proper contraception during the study. You must also be generally healthy enough to follow a new diet and be able to stick to the study's instructions and attend sessions.

You wouldn't be able to join if you have certain other health conditions, such as a confirmed H. pylori infection (a type of stomach bug), coeliac disease, an eating disorder, or if you're taking specific medications like anti-inflammatory drugs. Also, if you have other digestive problems like irritable bowel syndrome (IBS), severe acid reflux (GERD), or certain structural issues in your digestive system, you wouldn't be able to take part. Your BMI also needs to be within a certain range (not too low or too high).

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.

I am between 18 and 64 years old.
I have been diagnosed with functional dyspepsia by a doctor (ongoing stomach pain/discomfort with no other obvious cause).
I can read and write in English.
I understand I need to give written permission (consent) to take part.
I do not have other conditions like coeliac disease, an eating disorder, or severe acid reflux.
I am not currently pregnant or planning to become so during the study (if I'm a woman who could get pregnant).

Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will first involve assessing your current diet to understand how many ultra-processed foods you typically eat. This may include filling out questionnaires about your eating habits. Depending on these results, you might be invited to the next stage.

If you move to the second stage (the diet change part), you will switch to a 'minimally processed food' diet. This means focusing on natural, whole foods and cutting down on highly processed items. You won't be left to do this alone; you'll receive support to help you make these dietary changes and build healthier habits that can last. Throughout this stage, which lasts for three months, the researchers will check in with you regularly. They will track your symptoms, how you feel overall (your quality of life), and other health markers. This might involve more questionnaires and possibly some blood tests. There are no specific medications given as part of this study, as it focuses on diet and lifestyle. The total duration for those who take part in the dietary intervention is three months.

Potential risks and benefits

You might not personally feel better or see direct changes from taking part in the initial observational part of this study. However, the information gathered is very valuable and will help researchers understand functional dyspepsia better, which could lead to improved treatments for others in the future. If you are invited to the dietary intervention phase, you could potentially benefit. By making supported changes to eat healthier and be more active, you might experience an improvement in your digestive symptoms and your general health and wellbeing. There are some minor risks involved, such as slight discomfort from blood tests and discussing sensitive topics in questionnaires. The study organisers consider the overall risks to be low, and major side effects are not expected. 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.

University College London Hospitals NHS Foundation Trust
City only
London, England
University College London Centre for Obesity Research
City only
London, England

Common questions

What are 'ultra-processed foods' (UPFs)?

UPFs are foods that have been changed a lot during their making. They often contain extra ingredients like preservatives, flavourings, and artificial colours.

What is 'functional dyspepsia'?

It's a common stomach problem causing pain, bloating, or feeling full quickly in your upper stomach, without any clear other cause found by doctors.

Will I have to change my diet if I join?

Initially, no. The first part observes your current diet. If you eat a lot of UPFs, you might then be invited to a second stage where you'd be supported to try a minimally processed food diet.

How long will the study last if I take part in the diet change?

If you join the diet change part, it will involve three months of dietary support and symptom tracking.

Where is the study happening?

The study is organised by University College London (UCL) and participants will be identified from patients at University College London Hospital (UCLH).

How to find out more

Benjamin Norton

benjamin.norton@nhs.net +44 (0)20 3549 5979 Official trial record

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