You may know that eating well is important for your overall health and wellbeing, but not be aware of all the benefits. Good nutrition can:
- give you more energy and strength
- help you achieve or maintain a healthy weight
- improve your mood
- help prevent or reduce the risk of some conditions, such as heart disease, type 2 diabetes and even some cancers.
What to eat
The Australian Dietary Guidelines provide advice on eating for health and wellbeing for the general population. They were developed by the National Health and Medical Research Council (NHMRC). Five key recommendations include:
- achieve and maintain a healthy weight by being physically active and choosing nutritious food and drinks to meet your energy needs
- enjoy a wide variety of nutritious foods from the 5 food groups every day
- limit your intake of alcohol and foods containing saturated fat, added salt and added sugars
- encourage, support and promote breastfeeding
- care for your food – prepare and store it safely.
Use small amounts of fats such as butter and cooking oils and choose varieties that are low in saturated and trans fats. If you choose to eat fast food, processed meats and sweets and drink alcohol, only have them sometimes and in small amounts.
What to drink
Fluids are essential for the body to function. All the organs, tissues and cells in your body need fluids to keep working properly.
As a general guide, you should aim to drink at least 8–10 glasses of fluid per day. Most of this should be plain water, but fluid from soups, smoothies, milk, fruit juices, or ice cubes is also good. Tea and coffee also provide fluid, but they may cause you to urinate (pee) more often.
Alcohol may lead to weight gain and increase the risk of heart disease, type 2 diabetes and several cancers. When it comes to cancer risk, there is no safe level of alcohol consumption. For healthy people who choose to drink alcohol, Cancer Council recommends you follow the NHMRC guidelines and have no more than 10 standard drinks a week and no more than 4 standard drinks on any one day.
The benefit of eating well
Cancer and its treatment place extra demands on the body. Research shows that eating well before, during and after cancer treatment can help:
- improve quality of life by giving you more energy, keeping your muscles strong, helping you stay a healthy weight and boosting mood
- your body cope with the side effects of treatment, improve how well treatment works, reduce length of hospital stays and speed up recovery
- heal wounds and rebuild damaged tissues after surgery, radiation therapy, chemotherapy and other treatments
- improve your immune system and ability to fight infections
- reduce the risk of cancer coming back (recurrence).
How to eat well after a cancer diagnosis
During cancer treatment and recovery, you may need to adapt what you eat to help meet your body’s changing needs.
Preparing for treatment
- Try to eat as well as you can before starting treatment.
- Eat a wide variety of foods from the 5 food groups and do some physical activity to build muscle (if you are feeling well enough).
- If you have lost weight or you are not eating as well as usual, you may need food with more energy (kilojoules, also known as calories) and protein.
- Ask your GP or oncologist for a referral to a dietitian for advice about what to eat. You can also be referred to other health professionals, such as physiotherapists, exercise physiologists and psychologists, who can help prepare you for cancer treatment.
- Plan for days you don’t feel like cooking. Fill your freezer with frozen meals.
- Organise a meal roster with family and friends.
- You may need to be more flexible with what you eat. This may mean that the foods you are able to eat are quite different to those in your normal diet, and perhaps not foods that are recommended as part of a healthy diet.
- Alcohol can interact with some medicines. Check with your doctors before drinking wine, beer or spirits during cancer treatment.
- You may need food with more energy and protein.
- If you don’t have much of an appetite, try eating small, frequent meals or snacks, rather than 3 large meals a day.
- Ask for a referral to a dietitian if you are experiencing ongoing or fast weight loss.
- Do regular physical activity to improve appetite and mood, reduce fatigue, help digestion and prevent constipation. Exercise professionals such as a physiotherapist or exercise physiologist can help you develop an exercise plan.
- Check with your doctor or dietitian before taking vitamin or mineral supplements or making major changes to your diet.
- Look out for signs of malnutrition.
- Try to maintain your weight to help you recover faster.
- Eat a wide variety of foods and do some physical activity to rebuild muscle and help you recover from the side effects of cancer treatment. For help developing an exercise plan, see a physiotherapist or exercise physiologist.
- See a dietitian for support and help.
- Focus on healthy eating once you’ve recovered from the side effects of treatment.
- Maintain a healthy weight and be physically active to help lower the chance of cancer coming back.
- Limit how much alcohol you drink. If you choose to drink, have no more than 10 standard drinks a week and no more than 4 standard drinks in one day.
- Visit your doctor for regular check-ups and see a dietitian for support.
- Learn more about living well after cancer.
Living with advanced cancer
- Good nutrition can improve quality of life.
- Adjust what you eat to meet your changing nutritional needs.
- Talk to your doctor about medicines that may improve your appetite.
- Relax usual dietary restrictions, e.g. use full cream rather than low-fat milk.
- Consider nutritional supplements if you can’t eat enough. Discuss options with your doctor, palliative care specialist or dietitian.
- Learn more about advanced cancer.
The following questions are commonly asked by people affected by cancer. If you have a different question about food and cancer, speak with an accredited practising dietitian or visit iHeard to bust common cancer myths.
Before changing what you eat, following a specific diet or taking new or more vitamins or mineral supplements, it is important to talk to your doctor or dietitian. They can discuss the advantages and disadvantages of any changes, and ensure they are safe during and after cancer treatment.
Can food cause cancer?
The link between food and cancer is complex. There are many different types and 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 not always known. Poor eating habits combined with smoking, too little exercise, drinking too much alcohol, being overweight and too much sunlight exposure may, over a long period of time, increase the risk of developing some cancers.
Should I avoid alcohol?
Drinking alcohol increases the risk of developing some cancers, particularly cancers of the mouth, throat, oesophagus, stomach, bowel, liver and breast. Mouth cancers are six times more common in people who drink alcohol than non-drinkers.
The type of alcohol you drink – wine, beer, spirits – doesn’t make a difference. But drinking alcohol doesn’t mean that you’ll definitely get cancer. Your risk will depend on other factors, including your age and genetics.
Cancer Council recommends drinking less alcohol to reduce your risk of cancer. Drinking less alcohol has lots of other benefits too, including helping to reduce your risk of accidents, high blood pressure and liver disease.
Should I avoid processed meats and red meat?
The World Health Organization (WHO) classifies processed meats such as bacon, ham and salami as Group 1 carcinogens. This means there is a definite link with cancer. WHO puts processed meats in the same category as other proven causes of cancer such as tobacco, alcohol and ultraviolet (UV) radiation.
WHO classifies red meat as a Group 2A carcinogen. This 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. To reduce cancer risk, Cancer Council and the Australian Dietary Guidelines recommend that you:
- eat little, if any, processed meat such as bacon, ham and salami
- aim for no more than 455 g of cooked lean red meat (e.g. beef, lamb, pork, kangaroo, goat) per week. This could be one serve a day (65 g cooked) or 2 small serves at 3–4 meals a week.
You can swap a serve of red meat for fish, chicken, eggs or legumes (e.g. chickpeas or lentils) and get adequate amounts of the nutrients you need. If you are losing weight or finding it hard to eat enough during cancer treatment, ask your doctor or dietitian what foods to eat to help you get enough energy and protein.
Is organic food better?
Organic farmers and food producers grow and produce food without using synthetic pesticides or fertilisers. They also don’t expose food to radiation to extend shelf life, or use seeds, plants or animals that have had their genetic make-up altered in a laboratory.
Some people believe it’s better to eat organic foods because they don’t have extra chemicals. However, 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 those grown in the usual way and can be more expensive to buy.
Wash all fruit and vegetables thoroughly before you eat them. Focus on eating a wide variety of fruits and vegetables, rather than whether or not they’re organic.
Should I follow a special diet?
Some people claim that a particular diet or way of life can cure or control cancer on its own. Often these diets are promoted on social media or in the traditional media. There are no special foods, diets or vitamin and mineral supplements that have been scientifically proven to cure cancer. There’s also no research that shows any particular foods can lower the chance of the cancer coming back.
Many unproven diets encourage people to:
- cut one or more food groups (e.g. all dairy or all grains)
- eat large amounts of specific fruits and vegetables or their juices
- take special or high-dose supplements.
Following an unproven diet may affect your energy levels, cause unwanted weight loss and fatigue and weaken your immune system. This may make it harder for you to cope with treatment and lead to malnutrition.
Buying large amounts of fruits and vegetables or supplements can be expensive. Cutting out specific foods can also make it harder to eat meals with your family, at restaurants or other people’s homes.
Should I take a supplement?
Vitamins and minerals are an essential part of a healthy diet and play an important role in the body’s immune system. It’s best to get your vitamins and minerals from eating whole foods, as these are easier for the body to absorb. Some people may need to take vitamin and/or mineral supplements during and after treatment, even if you eat a wide variety of foods.
Some people believe that taking high doses of certain vitamins will boost the body’s immune system during cancer treatment. However, there is little evidence to support this claim. In fact, some vitamin and mineral compounds can be toxic at high levels, and may affect how radiation therapy, chemotherapy and other medicines work.
If your appetite is poor or if you’re concerned you’re not getting enough vitamins or minerals, check with your doctor or dietitian before taking any vitamin or mineral supplements.
Does sugar feed cancer?
Sugar is a type of carbohydrate found naturally in fruit and dairy products. It is also added to soft drinks and many processed foods. Our body uses sugar for energy.
You may hear that because cancer cells use sugar to grow, cutting out all sugar and carbohydrates from your diet will stop the cancer growing. This is a myth and can be harmful.
Cancer cells will get the energy they need to grow from other body tissues even if there are no carbohydrates available. The healthy cells in your body also use sugar to grow, so changing your diet in this way would mean missing out on the sugar that helps your vital organs work.
It’s a good idea to limit drinks with high amounts of added sugar such as soft drinks, cordials and sports drinks.
Foods and drinks high in sugar may cause you to put on weight. If you are losing weight or struggling to eat enough, having foods with sugar in them may help to keep your energy levels up. Talk to a dietitian about what to eat after a cancer diagnosis.
Is fasting a good idea?
Some people think that eating very little or no food for a specific period of time (fasting) helps treat cancer, but there is not enough evidence to support this idea, and it can be harmful.
Not eating enough can leave you feeling tired, cause you to lose muscle and weight, weaken your immune system and affect your ability to cope with treatment. These outcomes may lead to treatment delays or a shorter course of treatment.
It is important to try to eat enough of a wide variety of foods to meet your body’s needs, so you maintain strength during treatment. Speak to your dietitian and treatment team before trying any fasting techniques.
How important is exercise?
Along with eating well, physical activity is important for general health and wellbeing. Adults should aim to be active on most, preferably all, days of the week. Any physical activity is better than none. The aim is to be as physically active as your abilities and condition allow.
The advice used to be to rest during cancer treatment, but now exercise is recommended for most people during and after treatment. Research shows that regular physical activity can:
- help manage fatigue and other common side effects of treatment
- increase appetite
- speed up recovery
- strengthen muscles and bones
- improve circulation
- reduce the risk of the cancer coming back (for some cancer types) and of developing other health problems
- improve quality of life by reducing stress and improving mood.
Talk to your treatment team or GP before starting an exercise program, and see a physiotherapist or exercise physiologist to develop an exercise plan that suits your situation. A physiotherapist or exercise physiologist may be part of the team at your hospital or treatment centre, or your GP can refer you to one in private practice.
Should I see a dentist before starting treatment?
Cancer treatment often causes side effects that affect your mouth and teeth, such as dry mouth, mouth ulcers, tooth decay and mouth infections. These problems can make it hard to eat, and poor oral health can make them worse. This is why it is important to have a check-up with your dentist before treatment starts, especially if your treatment includes radiation therapy to the head or neck, some types of chemotherapy, or the drugs known as bisphosphonates (used to treat bone disease).
Your dentist can check the health of your teeth and find any problems early. You can also ask your dentist or your cancer treatment team for advice about caring for your teeth and mouth before, during and after treatment.
Can diet reduce the risk of cancer coming back?
After cancer treatment, you might think about changing what you eat to reduce the risk of cancer coming back. There’s no research that shows any particular foods or eating plan can lower the chance of the cancer coming back.
To reduce your risk of cancer, follow the Australian Dietary Guidelines and Australia’s Physical Activity and Sedentary Behaviour Guidelines for Adults. These are similar to the World Cancer Research Fund International’s cancer prevention recommendations.
Caring for someone with cancer
If you’re caring for someone with cancer, you may need to help them manage eating issues. It’s natural to worry that the person you’re caring for isn’t eating well or is losing weight, but try to avoid tension about food, as this may only increase their anxiety and yours.
Being a carer can bring a sense of satisfaction, but it can also be exhausting and stressful. Trying to prepare food for someone who is having trouble eating can be especially challenging. It is important to look after your own wellbeing, so you also need to eat well and get some exercise.
Give yourself some time out and share your concerns with somebody neutral such as a counsellor or your doctor.
Tips to support the person you're caring for with nutrition
- Ask them what they’d like to eat.
- Gently encourage them to eat foods that are high in kilojoules and protein when they are feeling well.
- Serve small amounts of food at a time and freeze the leftovers.
- Have ready-to-eat food available for when they feel like eating (e.g. tinned fruit, yoghurt, frozen meals).
- Keep mealtimes flexible and be willing to try new ideas or recipes.
- Offer their favourite foods at the times when you know their appetite is good.
- Make meals as enjoyable as possible – play music, set the table with candles and flowers.
- Take care to prepare food safely.
- Accept that during treatment the focus of the person with cancer may need to be on simply eating something, rather than on eating nutritious food all of the time.
Nutritional needs of children with cancer
The nutritional needs of children with cancer are different to adults, as children continue to grow and develop during treatment. The treatment team will monitor the weight and growth of your child closely during treatment.
- Be flexible – let your child eat when they feel like it, not just at mealtimes. Be flexible in what they eat. For example, allow them to have breakfast cereal for dinner if that’s what they prefer.
- Offer nutritious food – try not to make an issue of your child’s lack of appetite. Instead, encourage them to eat nutritious, high-kilojoule foods when they are feeling well.
- Allow occasional treats – during treatment, any nourishment is better than none. Allow your child to eat fatty or sugary foods like cake, chips, chocolate and takeaway occasionally.
- Eat at the table – discourage your child from eating in front of the television or computer as it can be distracting.
- Make mealtimes fun – focus on making mealtimes as relaxed as possible and see them as an opportunity to come together to share stories and discuss any concerns. Regular family meals also give a child a sense of stability.
Expert content reviewers:
Jacqueline Baker, Senior Oncology Dietitian, Chris O’Brien Lifehouse, NSW; Lauren Atkins, Advanced Accredited Practising Dietitian, OnCore Nutrition, VIC; Dr Tsien Fua, Head and Neck Radiation Oncology Specialist, Peter MacCallum Cancer Centre, VIC; Rosemerry Hodgkin, 13 11 20 Consultant, Cancer Council WA; Clare Hughes, Manager, Nutrition Unit, Cancer Council NSW; John Spurr, Consumer; Emma Vale, Senior Dietitian, GenesisCare, SA; David Wood, Consumer.
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The information on this webpage was adapted from Nutrition for People Living with Cancer - A guide for people with cancer, their families and friends (2022 edition). This webpage was last updated in July 2022.