Why diet is important

Eating a healthy balanced diet can help you cope with cancer and its treatments.

This page is about trying to achieve a balanced diet when possible for those with existing diet problems.

A healthy diet is also an important part of getting ready for cancer treatment. This preparation is called prehabilitation. Prehabilitation includes a focus on what you eat, your weight, physical activity and mental health.

How eating well helps

Eating and drinking a balanced diet is important when you have cancer. It can help you feel better. You may have more energy and it could help you cope better with your cancer and treatment side effects.

Having a healthy balanced diet can also:

  • help with wound healing, for example after surgery

  • help our immune system to work well and cope better with infection

  • reduce the risk of other conditions such as heart disease or diabetes

A balanced diet means eating foods from all the food groups that your body needs. But for many people with cancer, eating and drinking well can be a struggle. 

Your healthcare team can discuss ways to support you with eating and drinking. And there are things you can do to help yourself.

A balanced diet

Try to eat foods from all food groups to include everything your body needs to work well. These include:

  • fruit and vegetables

  • starchy carbohydrates such as potatoes, bread, rice and pasta

  • dairy products such as milk, yoghurt and cheese or dairy alternatives that have added calcium

  • proteins like beans, pulses, fish, eggs and meat

  • fats like oil and spreads

Drink 6 to 8 glasses each day. For example water, sugar free drinks, milk, tea and coffee.  

The diagrams below show how much of each food group you should eat each day to follow a healthy, balanced diet. They are also called Eatwell Guides. This is general information about a varied diet and recommended portions. If you have problems that are affecting your diet, your healthcare team may suggest that you change the amounts you eat from each group. 

Diagram showing Eatwell guide
Diagram showing African and Caribbean Eatwell Guide
Diagram showing South Asian Eatwell Guide

The NHS have produced a booklet called ‘Healthier Eating; African, Caribbean and South Asian cuisine’ as part of a Diabetes Prevention Programme. This information can be used by anyone try to follow a healthy diet.

Diagram showing Vegan Eatwell Guide

For general information and support contact the Cancer Research UK nurses on freephone 0808 800 4040 Monday to Friday, 9am to 5pm.

  • Nutrition support in adults 
    National Institute for Health and Care Excellence (NICE), November 2012

  • The Eatwell Guide
    Public Health England, 2018

  • Nutritional screening of adults: a multidisciplinary responsibility
    BAPEN (British Association of Parenteral and Enteral Nutrition), 2003

  • Nutrition in cancer patients
    P Ravasco
    Journal of Clinical Medicine, 2019. Volume 8. Page 1211

  • Molecular nutritional immunology and cancer
    R Çehreli
    Journal of Oncological Sciences, 2018. Volume 4. Pages 40-46

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in.

Last reviewed: 
25 Mar 2024
Next review due: 
25 Mar 2027

Related links