INFILTRATE Study
Learn more about the INFILTRATE study, testing the feasibility of a dietary intervention to help people with obesity and kidney failure lose weight to become eligible for a kidney transplant.
About the study
People living with obesity often face unequal access to kidney transplantation, even though current guidelines state that obesity alone should not prevent someone from being assessed or considered for a transplant.
There is currently limited evidence to guide healthcare professionals on how best to support people with obesity and kidney failure who are receiving haemodialysis to lose weight and become eligible for transplantation.
This study aims to address this gap. We are carrying out a randomised feasibility study to test a low-energy, formula-based total diet replacement programme (called INFILTRATE). The goal is to help people on haemodialysis lose weight and improve their chances of being listed for a kidney transplant.
The study is being conducted at the Royal Free Hospital and the Royal London Hospital. It has been approved by the Health Research Authority (HRA) and received ethical approval from the South Central – Oxford A Research Ethics Committee (reference: 26/SC/0041).
Who can take part?
You are eligible for this study if you are 18-70 years old, living with kidney failure and obesity, on haemodialysis/kidney therapy, awaiting listing for a kidney transplant, and able to give informed consent.
For more information, please download the Participant Information Sheet by clicking the link in our useful links section below or contact the study team directly.
How long will the study last?
From the screening visit, this study will last approximately 14 months.
Do I have to take part?
Taking part is entirely voluntary. If you decide not to take part, your usual care will not be affected in any way. If you do take part, you are free to withdraw at any time without giving a reason, and this will not affect your clinical care.
What will happen if I take part?
If you take part, you will attend six face‑to‑face study visits at your dialysis unit over 12 months. These include a screening visit and assessment visits at baseline, 3, 6, 9, and 12 months. If you are assigned to the diet programme, you will also have eight additional online check‑ins.
Screening visit
At the screening visit, a member of the research team will explain the study, answer your questions, and check whether you are eligible. If you agree to take part, you will be asked to sign a consent form. If eligible, a baseline visit will be arranged.
Baseline visit
At the baseline visit, we will take measurements such as weight, body fat, and blood pressure. You will also complete questionnaires, blood tests, and physical measurements. These help us understand your health before the study begins.
Randomisation
After the baseline visit, you will be randomly assigned to either the low‑energy diet programme or usual care. This is done by chance, like tossing a coin, and each group will have the same number of participants.
Low energy formula‑based diet
If you are in the intervention group, you will follow a nutritionally balanced, low‑energy diet using meal replacement products (about 850 calories per day). You will receive regular support from the research team and a specialist dietitian through an app, as well as tailored dietary and fluid advice. You will also have access to physical activity support, wellbeing group sessions, and a support group.
Usual care
If you are in the usual care group, your treatment will continue as normal with your healthcare team. This may include routine lifestyle advice and dietitian appointments. You will still attend study assessment visits every 3 months with the research team.
What are the benefits of taking part?
There may be no direct benefit from taking part. You may lose weight and become eligible for transplantation sooner, but this cannot be guaranteed. You will receive a £25 voucher for each study visit and contribute to research aimed at improving transplant access for people living with obesity.
What are the possible disadvantages of taking part?
You may not lose weight or become eligible for transplantation. The low‑energy diet may cause temporary side effects, which are usually mild and monitored closely by the study team. You will be asked to report any side effects, and support will be provided if problems arise.
What will you do with the information that you collect about me?
We will use information from you and your medical records only for this research study. Your data will be kept secure, confidential, and handled according to privacy regulations. Any findings will be anonymised so you cannot be identified, and some data may be securely stored for future research.
FAQs
Here are some frequently asked questions to help you learn more about the INFILTRATE study and what taking part involves. For further information, please contact the study team directly using the email address at the bottom of this page.
The project lead is Dr. Adrian Brown. Other team members are Claudia Hobbs his research assistant; Professor Reza Motallebzadeh; Dr Helen MacLaughlin; Dr Kieran McClafferty; Dr Sebastian Potthoff; Professor Rachel Batterham; Dr Sharlene Greenwood; Dr Victoria Vickerstaff; Dr Sarah Afuwape and Anna Bell-Higgs/Bjorn Ronaasen from Counterweight.
This study/project is funded by the National Institute for Health Research Advanced Fellowship (NIHR303041).
We are passionate about improving access to kidney transplant surgery for patients living with obesity.
A feasibility study is a small, early study that helps us find out whether a new programme or approach can work in practice. In this case, it means checking how helpful and easy to use the weight loss programme is, and whether it would be worth testing it in a larger study in the future.
If you decide to take part, we will arrange a screening visit. This will take place at a convenient time for you, i.e. during your haemodialysis session at your hospital. A member of the research team will explain the study to ensure that you understand the purpose of the study and to answer any questions that you may have. If you are happy to proceed, we will ask you to sign a consent form and provide you with a photocopy for your records. If you are eligible, we will arrange a convenient time for the baseline visit, during which additional measurements will be taken; these are described in the supporting participant information sheet which you can download via the link in our 'useful links' section below.
If you are in the usual care group, your treatment will continue as normal with your healthcare team. This may include routine lifestyle advice and dietitian appointments. You will still attend study assessment visits every 3 months with the research team.
Useful links and resources
Participant information
Before taking part, please read our Participant Information Sheet carefully. This explains the study in detail, including what participation involves.
Download and read our Participant Information Sheet below.
Kidney support and information
These organisations provide trusted information, advice, and support for people living with kidney disease:
Kidney Care UK - practical support, patient stories, and financial advice
UK Kidney Association - information about kidney care and treatment
The Diary of the Kidney Warrior Podcast - personal experiences and conversations about living with kidney disease
Obesity support
If you would like additional support with weight management, the following groups may be helpful:
Obesity UK support groups - peer support and advocacy
UK Coalition for People Living with Obesity Support groups - support networks and resources
Eating well with kidney disease
These resources offer recipe ideas and practical guidance tailored for people with kidney conditions:
Kidney Kitchen UK Recipe ideas - recipes and dietary advice
Kidney Kitchen UK African and Caribbean Recipes - culturally diverse meal ideas
Cooking for your Kidney cooking videos by Imperial College Healthcare NHS Trust - step-by-step cooking guidance
Mental health support
Living with kidney disease or making lifestyle changes can be challenging. Support is available:
Mind - information and support for mental wellbeing
Contact the Study Team
Want to speak to us directly? Contact Adrian Brown or Claudia Hobbs below and include your name and preferred contact method. We look forward to hearing from you.
