On this page: Key nutritional needs of each treatment phase | Common questions
Cancer itself and cancer treatment place extra demands on your body. Nutrition and exercise will help you cope better.
How good nutrition can help
Research suggests that eating well benefits people during and after cancer treatment. It can help to maintain muscle strength, maintain a healthy weight and have more energy, all of which can improve your quality of life. Good nutrition can also help to:
- manage the side effects of treatment and speed up recovery
- heal wounds and rebuild damaged tissues – this is important after surgery, radiotherapy, chemotherapy or other treatment
- improve your body’s immune system and ability to fight infections
- reduce the risk of cancer coming back.
How exercise can help
According to research, exercise helps most people during and after cancer treatment. Being active may:
- strengthen your muscles and bones
- reduce your risk of developing new cancers and other health problems
- improve your circulation and energy levels
- reduce stress and improve your mood
- manage fatigue, a common side effect of many treatments.
Check with your doctor before starting an exercise program, or see a physiotherapist or exercise physiologist to develop an exercise plan that suits your situation. For more details see Exercise for People Living with Cancer or call Cancer Council 13 11 20.
Key nutritional needs of each treatment phase
During cancer treatment and recovery, you need to adapt what you eat to cope with your body’s changing nutritional needs.
- You may need more energy (kilojoules/calories). Eat small, frequent meals or snacks, rather than three large meals a day. See snack suggestions.
- If you start to lose weight, see practical suggestions on gaining weight. Ask for a referral to a dietitian if weight loss is an ongoing and significant issue.
- Do some light physical activity, such as walking, to improve appetite and mood, reduce fatigue, help digestion and prevent constipation.
- Check with your doctor or dietitian before taking vitamin or mineral supplements or making other changes to your diet.
- Try to maintain your weight to speed up recovery.
- Eat a variety of foods and do some physical activity to rebuild muscles and recover from treatment side effects.
- If you are still experiencing treatment side effects that impact on what you can eat and drink, continue to follow the relevant suggestions in the treatment side effects and nutrition section. You can also talk to a dietitian for further assistance.
Living with advanced cancer
- Good nutrition can help improve quality of life.
- Adjust your food choices and eating patterns to meet your changing nutritional needs.
- Talk to your doctor about medicines suitable for boosting your appetite.
- Relax dietary restrictions, e.g. choose full-cream rather than low-fat milk.
- Consider using nutritional supplements if you can’t eat enough. Discuss options with your doctor, palliative care specialist or dietitian.
- See the nutrition and advanced cancer section.
Good oral health
Before treatment starts, see your dentist to check the health of your teeth and to identify any problems early.
This check-up is especially important if you are having radiotherapy to the head or neck, as radiation can affect your teeth and gums.
Chemotherapy and bisphosphonates can also cause mouth and dental problems, especially if you already have poor dental health.
Your doctor or dentist can advise the best way to care for your teeth and mouth before, during and after treatment.
Can food cause cancer?
The link between food and cancer is complex. 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. Poor eating habits combined with other lifestyle factors (such as smoking, too little exercise, drinking too much, being overweight and too much sunlight exposure) may, over a long period of time, increase the risk of developing some cancers.
Does excess food feed the cancer?
Cancer does not grow from eating too much food. Some people think that fasting helps treat cancer, but there’s no evidence to support this. Not eating enough can leave you feeling weak and affect your ability to cope with treatment. The important thing is to try to eat a wide variety of food, and to eat enough to meet your body’s needs.
Some people worry that eating food with sugar makes the cancer grow faster. To manage this, they may eliminate all sugar from their diet, but this may mean they miss out on beneficial food such as fruit.
Should I avoid processed meats and red meat?
Recently, the World Health Organization classified processed meats such as bacon and salami as a Class 1 carcinogen. This means there is a definitive link with cancer, and it puts processed meats in the same category as other causes of cancer such as tobacco, alcohol and ultraviolet radiation. Red meat has been classified as a Class 2A carcinogen, which means it probably causes cancer, but the evidence isn’t as strong.
These classifications do not indicate the risk of getting cancer; they describe the strength of the evidence that these foods are linked to cancer.
Cancer Council recommends limiting or avoiding eating processed meats such as bacon and salami. You don’t have to stop eating red meat during or after treatment, but limit serves to 65–100 g of lean red meat (e.g. beef, lamb, pork, kangaroo, goat) 3–4 times a week (maximum of 455 g a week). Add extra vegetables to your plate, or try fish, eggs, chicken or legumes (such as chickpeas or lentils) instead of red meat.
Is organic food better?
Organic farmers and food producers grow and produce food without pesticides or fertilisers. They also don’t use genetically modified components or irradiate food. Some people believe it’s better to eat organic food because they’re not eating extra chemicals in their food.
There is no strong evidence that organic food is better for you, or that it will help you recover faster or reduce the risk of cancer coming back.
Organic fruits and vegetables contain the same vitamins and minerals as conventionally grown produce. However, they can be more expensive to buy. Focus on eating a variety of fruits and vegetables, rather than whether or not they’re organic.
Should I follow a special diet?
People often ask what they should eat after a cancer diagnosis. They may consider changing their diet to help their body cope with the effects of cancer and its treatment, and to give themselves the best chance of recovery.
Some people claim that a particular diet can cure or control cancer on its own. However, there are no special foods, diets or vitamin and mineral supplements that have been scientifically proven to do this. These unproven diets often encourage people to eliminate one or more basic food groups, include large amounts of specific fruits, vegetables or their juices, and to take special supplements.
Unproven diets, particularly those that suggest cutting out whole food groups, are likely to be low in energy (kilojoules/ calories), protein, fat, iron, calcium, zinc and vitamins. Following one of these diets can cause unwanted weight loss and tiredness, and lower your immune function. This may make it harder for you to cope with treatment and lead to malnutrition. Unproven diets are often expensive and can prevent you from enjoying social occasions.
Before changing what you eat, following a specific diet, or taking large quantities of vitamins or mineral supplements, talk to your doctor or dietitian. They can discuss the advantages and disadvantages of different diets. For more information see Understanding Complementary Therapies or call Cancer Council 13 11 20.
Juice therapy involves using fresh fruit and vegetable juice as the main source of food. Supporters claim it improves the immune system, reduces blood pressure and helps to clean out (detoxify) the body.
The health benefits of whole fruits and vegetables are well known, but the benefits of juice therapy are not. By drinking only juice, you miss out on the fibre contained in whole fruits and vegetables. This may lead to weight loss and malnutrition.
It’s best to drink fresh fruit and vegetable juices as part of a healthy balanced diet.
Reviewed by: Amber Kelaart, Senior Dietitian, Nutrition & Speech Pathology Department, Peter MacCallum Cancer Centre, VIC; Monica Conway, Assistant Nurse Manager, Cancer Information and Support Service, Cancer Council Victoria, VIC; Anne Finch, LiveLighter Project Officer, Cancer Council Western Australia, WA; Clare Hughes, Nutrition Program Manager, Cancer Council NSW, NSW; Tanya King, Senior Oncology Dietitian, Coastal Cancer Care, Sunshine Coast University Private Hospital, QLD; Tony Southwell, Consumer; Klara Suessenbach, Health Promotion Officer, Cancer Council Tasmania, TAS.