Eating well before treatment

People often ask what they should eat when they have cancer. There is no eating plan that is proven to cure cancer and there are no special foods to eat or avoid if you have cancer. 

Treatment for cancer can place extra demands on your body, making eating well more important than ever. Good nutrition helps you get the most benefit from your treatment.

Have a dental check–up prior to treatment to ensure that your teeth are in good condition, and to identify any possible problems before you begin your treatment. This is particularly important if you are having radiation to the head or neck, as this can impact on the health of your teeth.

After treatment your mouth and gums may be too sensitive for dental work. Your dentist, nurse or doctor can advise you of the best way to care for your teeth and mouth before, during and after your treatment.

Discuss any changes to your diet and any vitamin, herbal or nutritional supplements you are taking with your doctor and dietitian before starting treatment. If you smoke or drink alcohol, inform your doctor before you start treatment.

  • If you are underweight, this is a good opportunity to gain weight so you start your treatment at a healthy weight.
  • If you are losing weight without trying ask your doctor for a referral to a dietitian.
  • If you are overweight or trying to lose weight, change your focus to weight maintenance prior to and during your treatment.
  • If you are having no problems eating prior to treatment, check and aim to maintain your weight.
  • Plan ahead to make your treatment period as easy as possible. Friends and family often ask what they can do to help, so ask a friend or relative to do your grocery shopping for a few weeks or make up some frozen meals that you can reheat if you don’t feel like cooking.
  • Book in with your dentist fora check–up before starting treatment.

Benefits of eating well

Eating well is important for everyone but especially for those who have been diagnosed with cancer. Good nutrition can:

  • help you to cope better with treatment side effects and to recover sooner
  • help wounds and damaged tissues to heal better. This is important before and after surgery, radiotherapy, chemotherapy or other medical treatment improve your body’s immune system – its natural defence – so you are better able to fight infection
  • help you to maintain muscle strength, stay a healthy weight, have enough energy for everyday tasks and to feel better in yourself.

Eating well is something you can control during your cancer treatment and can enhance your quality of life.

How treatment affects eating

The common ways to treat cancer include:

  • surgery – cancer is removed during an operation
  • chemotherapy – medications are used to cure or control cancer
  • radiotherapy – x–rays and gamma rays are used to cure or control cancer.

Cancer treatment often damages normal healthy cells at the same time as killing cancer cells. This may produce side effects that can affect eating, such as:

  • loss of appetite
  • feeling sick (nausea)
  • feeling tired (fatigue)
  • having a sore mouth
  • having a sore throat and trouble swallowing
  • having a dry mouth
  • changes in taste and smell
  • constipation or diarrhoea.

Side effects vary from person to person. The part of the body treated, the length of treatment and the dose of treatment all determine whether side effects will occur. Most side effects are temporary and go away after treatment ends. There are ways to control and manage the side effects.

Worrying about your illness, feeling anxious or afraid can also affect your eating. Talk to someone you trust, the social worker at the hospital or your doctor, if you are experiencing these feelings.

What should I eat?

Your body converts food into energy. This food energy is measured in kilojoules or calories. It is labelled as kJ for kilojoules on food packaging. Everyone needs a certain number of kilojoules each day to fuel their body for energy, growth and repair. You need energy even if you are not very physically active.

Throughout the phases of cancer treatment and recovery, it is important to adapt what you eat to cope with your body’s changing nutritional needs. Here is a summary of the key nutritional needs in each phase.

Phase 1 – Cancer treatment

  • You may need more energy (kilojoules/calories). Eat small, frequent meals or snacks, rather than three large meals a day.
  • If you start to lose weight, try eating extra nutritious snacks or drinks.
  • If possible, do some light physical activity, such as walking, to improve appetite, reduce fatigue, help digestion and prevent constipation. Check with your doctor or dietitian if you want to take vitamin or herbal supplements.

Phase 2 – Recovering from treatment

  • Continue to follow all the tips in Phase 1 for weeks or even a month or two following treatment. Nutritional needs remain high following treatment, and will differ depending on your cancer type and the treatment you’ve had. Your doctor or dietitian can advise you on your individual needs during this time.
  • It is important to maintain a minimum weight during this time to ensure your recovery from treatment is as quick as possible.
  • It is important to eat a variety of foods and to do some physical activity, as you’re able, in order to rebuild muscles and recover from the side effects of treatment.
  • If you are still experiencing treatment related side effects, you may need to follow some of the suggestions given in the section for during treatment until they resolve. Your dietitian can advise you during this time.

Phase 3 – Preventing cancer recurrence and new cancers

  • Once you’ve recovered from the side effects of treatment and you’re eating well and physically active, you can switch the focus of nutrition to healthy eating.
  • Healthy eating, maintaining a healthy weight and being physically active can help to lower the chance of cancer coming back.
  • Eating plenty of fruit and vegetables may lower the risk of developing some cancers. Try to eat at least two serves of fruit and five serves of vegetables every day.
  • See your doctor for regular checkups.
  • Contact Cancer Council Helpline 13 11 20 for free information about eating well and being active after treatment.

Living with advanced cancer

  • Good nutrition can help to maintain quality of life.
  • You may need to adjust your food choices and eating patterns to meet changing nutritional needs.
  • Medications and physical activity can boost appetite. Talk to your doctor about suitable options for your situation.
  • Nutrition supplements may help if you can’t eat enough. Talk to your doctor, palliative care specialist or dietitian.
This information was last reviewed in June 2013

This information has been reviewed by: Jenelle Loeliger, Head – Nutrition Department, Peter MacCallum Cancer Centre, VIC; Kate Aigner, Cancer Information Consultant, Cancer Council Helpline ACT; Ian Anderson, Consumer; Anna Boltong, PhD Candidate (Dietitian), Department of Cancer Experiences Research, Peter MacCallum Cancer Centre, VIC; Clare Hughes, Nutrition Program Manager, Cancer Council NSW; Bridget Kehoe, Public Health Coordinator (Nutrition and Physical Activity), Cancer Council QLD; Steve Pratt, Nutrition and Physical Activity Manager, Cancer Council WA; and Roswitha Stegmann, Helpline Nurse, Cancer Council WA.

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