A trial of supported weight loss before surgery for bowel cancer (CARE Trial)

Cancer type:

Bowel (colorectal) cancer
Colon cancer
Rectal cancer





This trial is looking at a programme to help people lose weight before surgery for bowel cancer. 

It is for people who are carrying excess weight.

More about this trial

Surgery is a usual treatment for bowel (colorectal) cancer. Some people have a risk of developing complications from surgery. We know that people who have complications recover more slowly, have longer hospital stays, and need more care.

In this trial, researchers are trying to find ways to reduce these complications. Physical fitness and having well controlled blood sugar are linked with better recovery after surgery. Losing weight improves physical fitness and helps control blood sugar for people who carry excess weight. The team think that this could lower the number of complications that surgery can cause. 

The main aims of the trial are to find out:

  • how practical it is to lose weight between getting a bowel cancer diagnosis and surgery
  • if people are willing to take part in the trial

The team hope to run a larger trial with more people if this one is successful.

Who can enter

The following bullet points are a summary of the entry conditions for this trial. Talk to your doctor or the trial team if you are unsure about any of these. They will be able to advise you. 

Who can take part

You may be able to join this trial if all of the following apply. You:

  • are due to have surgery for bowel (colorectal) cancer with the aim to cure
  • have completed chemotherapy if your treatment plan includes chemotherapy before your operation (neo adjuvant chemotherapy)
  • can speak and understand English or you have a relative, friend, or carer who can translate for you
  • have a body mass index (BMI) Open a glossary item of 28 or more. Or you have a BMI of 25 or more if you are Black, Asian or of minority ethnic origin. Your doctor or nurse work out your BMI by measuring your height and weight.
  • are well enough to be up and about for more than half the day (performance status 0, 1 or 2)
  • are at least 18 years old

Who can’t take part

You cannot join this trial if any of these apply. You:

  • have lost more than 10% of your body weight in the 6 months before you join the trial
  • are having your surgery within 20 days of checking to see if you are suitable for this trial
  • have had a scan that shows you are likely to develop a blockage in your bowel. Or you have had an endoscopy Open a glossary item that showed you have a large area of cancer that is blocking your bowel.
  • are allergic to soy 
  • have a serious problem with how your kidneys work 
  • have a serious problem with your heart  Open a glossary item
  • have had weight loss (bariatric) surgery
  • have type 1 diabetes
  • take a blood thinner medication called warfarin
  • are pregnant, planning to become pregnant during the trial or breastfeeding
  • are taking a drug or using a device as part of a clinical trial
  • have any other medical condition that could affect you taking part in this trial

Trial design

This trial is taking place in the UK. The team need to find 72 people to take part. 

It is a randomised trial. You are put into a group by a computer. Neither you nor your doctor will be able to decide which group you are in. 

There are 2 groups:

  • normal care group – you carry on with your normal care as usual 
  • supported care group – you follow the weight loss programme 

Normal care group 
You carry on with your normal care as usual. You don’t follow a special diet. 

Supported care group
You follow a special low calorie Open a glossary item diet. You start the diet as soon as you join the trial and continue up until 2 days before your surgery. This is for about 3 weeks on average. 

You eat only nutritious soups and shakes. The research team chose this diet because, on average, people who follow it lose more weight than people following diets based on eating less regular food.

The soups and shakes contain:

  • all the vitamins and minerals you need 
  • plenty of protein and fibre to help you feel full 
  • fewer calories than most people usually eat

Every day, you have 4 of the soups or shakes. You can choose from a variety of flavours. The team provide you with these products for free. They are gluten free and free of nuts, sesame, and shellfish. They are suitable for Halal, Hindu, or Kosher diets. And they are already used by the NHS in other medical conditions.

You will have a consultation once a week with a dietitian Open a glossary item. This is a phone or video call. These consultations stop when you finish the diet. 

In the supported care group, the team call you when you are halfway through the diet period. They ask you what you thought about the diet. This call takes about 45 minutes.

Quality of life
The trial team ask you to fill out some questionnaires:

  • when you join the trial 
  • at set times during the trial and afterwards

The questionnaire asks about side effects and how you’ve been feeling. This is called a quality of life questionnaire.

Hospital visits

You see the trial team at the hospital to see if you are suitable to join the trial. At this visit:

  • they discuss the trial with you and what it involves
  • they measure your weight and height
  • the team ask you some questions about yourself  
  • you do a sit stand test. This tests your leg strength. 

This initial visit takes about 2 hours. The team ask to audio record this visit. You don’t have to agree to this if you don’t want to. You can still take part in the trial.

The team check your weight again when you go into hospital for surgery. You also see them at the hospital 1 month after surgery. This is to see how you are. They repeat the assessments you had done when you joined the trial.

Side effects

The trial team monitor you while you are on the diet and for a short time afterwards. 
Most people won’t have side effects from the low calorie diet. A few people might develop constipation Open a glossary item. The team give you a fibre supplement to take to help prevent this. 

Other possible side effects of the low calorie diet include:

  • tiredness (fatigue)
  • headache
  • dizziness
  • dry mouth
  • tummy (abdominal) pain
  • bad breath
  • diarrhoea Open a glossary item
  • hair loss
  • dry skin
  • mood changes
  • feeling cold

Most of these side effects are mild and don’t last long. Your dietitian contacts you regularly. They can suggest things you can do to help manage your side effects.

We have information about preparing for cancer treatment (prehabilitation).



Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Dimitrios Koutoukidis

Supported by

National Institute for Health Research (NIHR)
Nuffield Department of Primary Care Health Sciences, University of Oxford
Surgical Intervention Trials Unit, University of Oxford

Other information

The trial team have made a video about the CARE trial and what it involves.

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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