On this page: Before treatment ι Benefits of eating well ι How treatment affects eating ι What should I eat? ι Can foods cause cancer? ι Can foods cure cancer? ι Does excess food feed cancer? ι Reviewers
People often ask what they should eat when they have cancer. There's no eating plan that's 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 before treatment to ensure your teeth are in good condition, and to identify any possible problems before you begin your treatment. This is particularly important if you're 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're taking with your doctor and dietitian before starting treatment. If you smoke or drink alcohol, inform your doctor before you start treatment.
- If you're underweight, this is a good opportunity to gain weight so you start your treatment at a healthy weight. For practical suggestions on how to increase your weight, see our Changes in your weight section.
- If you're losing weight without trying ask your doctor for a referral to a dietitian.
- If you're overweight or trying to lose weight, change your focus to weight maintenance before and during your treatment.
- If you're having no problems eating before treatment, follow the guidelines for healthy eating (which are the same as after 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 for a check–up before starting treatment.
Benefits of eating well
Eating well is important for everyone but especially for those who've been diagnosed with cancer. Good nutrition can:
- help you cope better with treatment side effects and to recover sooner.
- help wounds and damaged tissues 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're better able to fight infection.
- help you 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're experiencing these feelings.
Call Cancer Council on 13 11 20 for free booklets on chemotherapy, radiotherapy and specific types of cancer.
What should I eat?
Your body converts food into energy. This food energy is measured in kilojoules or calories. It's 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're not very physically active.
Throughout the phases of cancer treatment and recovery, it's important to adapt what you eat to cope with your body’s changing nutritional needs. Here's a summary of the key nutritional needs in each phase.
Phase 1: Cancer treatment
- You may need more energy (kilojoules/calories). See our practical suggestions on getting the most from food and using nutritional supplements. Eat small, frequent meals or snacks, rather than three large meals a day. See snack suggestions.
- 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's important to maintain a minimum weight during this time to ensure your recovery from treatment is as quick as possible.
- It's 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're still experiencing treatment related side effects, 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 on 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.
Can foods cause cancer?
There are many different types of cancer and many different causes of cancer, only some of which are understood. Cancer starts when cells begin to grow out of control. The reason for this change is unknown but lifestyle and diet can sometimes play a part.
It's unlikely that any one food or food additive is to blame. It's more likely that poor eating habits combined with other lifestyle factors, such as smoking, too little exercise, being overweight and having too much sunlight exposure may, over a long period of time, increase the risk of developing some cancers.
Can certain foods cure cancer?
There's no evidence to prove that eating certain foods can cure cancer. Be wary of advice that eliminates many types of food or whole food groups from your diet. Following this advice can negatively impact on your ability to cope with treatment and maintain daily activities. Eating a wide variety of foods helps to ensure you get all the nutrients you need. Always discuss changes to your diet with your dietitian or doctor.
Does excess food feed the cancer?
Cancer doesn't grow from eating too much food. Some people think that fasting is a good treatment for cancer but there’s no evidence to support this. Lack of food can leave you feeling weak and affect your ability to cope with treatment. The important thing is to try and eat a wide variety of foods, and enough to meet your body’s needs.
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.