Eating well and keeping active

After a cancer diagnosis, many people find that following a healthy, balanced diet and staying active helps give them back a sense of control.

Healthy eating

After a cancer diagnosis, many people find making the decision to follow a healthy, balanced diet helps give them back a sense of control. It can also help you feel that you are doing the best for your health.

Eating well and keeping to a healthy weight will help you keep up your strength, increase your energy levels and improve your sense of well-being.

After cancer treatment, some people have a higher risk of other health problems, including diabetes, heart disease or osteoporosis (bone thinning). If you have been told that you may be at an increased risk of any of these conditions, it is especially important to follow a healthy diet to help prevent them.

Before making changes to your diet, it can help to talk to a dietitian, your GP or a specialist nurse. This may be especially useful if you have any special dietary requirements or medical needs.

Following a cancer diagnosis people often have questions about their diet and what they should be eating and drinking. Macmillan Oncology Dietitians Lindsey Allan and Nicola Porter at the Royal Surrey NHS Foundation Trust have created 18 short videos about diet and cancer. These videos aim to increase people’s confidence in managing their diet before, during and after treatment.

We have more information about healthy eating and cancer.

Staying active

There are lots of benefits to staying active when you are living with cancer.

If you have just been diagnosed, physical activity can help you get as ready for treatment as you can be. It may reduce your risk of having side effects or mean side effects are less severe. It may help you recover more quickly.

During and after cancer treatment, staying active may help you:

  • maintain your fitness, strength, and mental well-being
  • manage ongoing side effects such as tiredness (fatigue)
  • reduce your risk of late effects after treatment.

Research also suggests that along with having a healthy diet, being physically active can help reduce the risk of some cancer types coming back.

Getting started

Being active before, during and after cancer treatment is generally safe. Any activity will help maintain or improve your fitness, health and well-being. Before starting any physical activity plan, it is important to talk to a healthcare professional.

If you need ideas to help you get started or advice about finding activities near you, our information about types of physical activity may help. We also have information about exercising safely when you have cancer.

There is not a single activity that is best for everyone. The important thing is to choose something that fits in with your life. If you already exercised before treatment, you may find you need to do it at a slower pace or lower intensity during treatment.

If you feel unfit and treatment is making you feel very tired, then you could start gently, by trying to:

  • reduce the amount of time you spend sitting or lying down
  • do some light housework or gardening
  • go for a walk.

Booklets and resources

We Are Undefeatable

We Are Undefeatable supports people with a range of long term health conditions, including cancer, to be active. Their website offers information, ideas and activity videos to help everyone find something that works for them.

About our information

  • References

    Below is a sample of the sources used in our eating well and keeping active information. If you would like more information about the sources we use, please contact us at

    Fang X et al. Quantitative association between body mass index and the risk of cancer: A global Meta-analysis of prospective cohort studies. International Journal of Cancer. 2018 Oct 1;143(7):1595-1603.

    British Nutrition Foundation website (accessed December 2019).

    Bhaskaran K et al. Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5·24 million UK adults. The Lancet, August 2014.

    The Eatwell Guide: Helping you eat a healthy, balanced diet, Food Standard Scotland, October 2019.

    Campbell K, Winters-Stone K, Wiskemann J, et al. Exercise guidelines for cancer survivors: consensus statement from international multidisciplinary roundtable. Med Sci Sports Exerc. 2019 November; 51911): 2375-2390 [accessed February 2023]. Physical activity for adults and older adults: 19 and over [accessed February 2023].

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist, and Professor Anna Campbell, Professor in Clinical Exercise Science at Edinburgh Napier University.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 November 2023
Next review: 01 November 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.