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Nutrition concerns

After some cancer treatments, you may have concerns about nutrition-related side effects. This is because cancer and treatment can affect how the body digests, absorbs and uses food.


Malnutrition in people with cancer occurs when you eat less energy and protein than your body needs. Factors that increase the risk of malnutrition include:

  • surgery for some cancer types, such as head and neck, lung and gastrointestinal cancers, which may make it difficult to swallow and to digest food
  • increased nutritional needs from cancer and treatments such as chemotherapy, radiotherapy and surgery
  • side effects from cancer treatments that make eating more difficult, such as nausea, vomiting and dry mouth
  • some medicines
  • stress, anxiety and fatigue.

Many of the eating issues discussed in the treatment side effects section can contribute to, or be symptoms of, malnutrition. Other signs include significant weight loss; confusion; dry, brittle hair and nails; and pale or pigmented skin.

Malnutrition can increase your risk of infection and reduce your strength, function and quality of life. It can affect how your body responds to cancer treatment and recovery. It is possible to be malnourished even if you are overweight. Talk to your doctor or dietitian if you think malnutrition is an issue.

More on malnutrition

Food safety

Cancer and some treatments such as chemotherapy and stem cell transplants can weaken the body’s immune system by affecting white blood cells that protect against infection. If you are having these treatments, you will be encouraged to take care preparing food as a weakened immune system can make you more susceptible to foodborne illness.

Making safer food choices
Food type Safe action  Precautions to take
chicken Cook thoroughly
  • Refrigerate leftover chicken immediately – don’t let it cool on the benchtop
  • Eat within 24 hours. Reheat until steaming hot
  • Avoid purchased, ready-to-eat chicken
meat Cook thoroughly
  • Refrigerate leftover food immediately – don’t let it cool on the benchtop
  • Eat within 24 hours. Reheat until steaming hot
seafood Eat well-cooked fresh seafood
  • Refrigerate leftover seafood immediately and eat within 24 hours
  • Avoid raw seafood (e.g. oysters, sashimi or sushi) and ready-to-eat peeled prawns
  • Avoid smoked, ready-to-eat seafood
cold meats (home cooked) Store in fridge
  • Avoid unpackaged ready-to-eat cold meats from the deli counter or packaged, sliced ready-to-eat cold meats
sandwich Eat freshly made
  • Avoid pre-made sandwiches
salad Wash thoroughly before preparing
  • Refrigerate leftover salad immediately, and eat within 24 hours
  • Avoid ready-to-eat or prepackaged deli salads, including pre-cut fruit salads
cheese Eat hard or processed cheese (e.g. cream cheese, cottage cheese)
  • Store cheese in fridge
  • Avoid soft, semi-soft and surface-ripened cheeses (e.g. brie, camembert, ricotta, fetta and blue)
other dairy products Store pasteurised milk, yoghurt and custard in fridge
  • Avoid unpasteurised or raw dairy products
packaged food Use within use-by dates
  • Store unused portions in fridge in clean, sealed containers and use within 24 hours
ice-cream Keep frozen
  • Avoid soft serve ice-cream
General precautions
  • Wash your hands and knives, cutting boards and food preparation areas thoroughly with hot soapy water before cooking.
  • Take care when eating out, as it can be difficult to know whether food safety guidelines are being followed. Where possible, ask for meals to be made fresh and avoid pre-prepared foods that have been sitting for unknown periods of time.

Managing eating side effects caused by surgery

Surgery that removes part of the digestive system, such as the oesophagus, stomach and bowel, will change the way you eat and digest food. Suggestions for coping with common dietary issues such as poor appetite, change in taste or smell, diarrhoea or nausea are covered in the treatment side effects and nutrition section.

Surgery for bowel cancer

When part of the bowel is removed, many people have more frequent bowel movements (diarrhoea). This usually improves in a few months, but it may take longer for some people. Your doctor or nurse might recommend a low-fibre diet to ease digestion.

If you have a stoma (a surgical opening in the abdomen that allows faeces to leave the body) after surgery, you may need to make some dietary changes until your body adjusts. See Understanding Bowel Cancer for more tips on coping with a stoma. Download a copy of the Australian Government’s Improving Bowel Function After Bowel Surgery booklet, or call 1800 33 00 66 for a copy.

Surgery to the head and neck area

Your ability to chew and swallow may be affected after surgery. If you are having difficulty eating or drinking, you may be given a temporary or permanent feeding tube. This tube can help you maintain or gain weight. More information is provided in Understanding Head and Neck Cancers.

Surgery for stomach cancer (partial gastrectomy or total gastrectomy) – Removing part or all of the stomach will affect what you can eat and how you eat. The change in structure of the stomach may mean that foods high in sugar move through the stomach faster. This may cause cramps, nausea, racing heart, sweating, bloating, diarrhoea or dizziness. This is called dumping syndrome, and it usually improves over time. Dietary changes and medicines can help. For further details, see Understanding Stomach and Oesophageal Cancers.

Surgery for oesophageal cancer (oesophagectomy)

Removing the oesophagus will change how you eat. After surgery, you will have a feeding tube, then progress to a liquid diet, followed by a diet of soft or moist foods. If you cough while eating or feel like the food is getting stuck in your throat when you swallow, consult your doctor and dietitian immediately.

Surgery for pancreatic cancer

This will cause a significant change to what you can eat and drink. Some people develop diabetes before being diagnosed with pancreatic cancer or soon after surgery. The way diabetes is managed varies from person to person, but it usually includes a combination of dietary changes and medicines. As your body may not be able to make enough enzymes to digest food after surgery, you may need to take enzyme supplements with every meal. For more information, see Understanding Pancreatic Cancer.

Changes in weight

Weight loss

This is common in people with cancer because the cancer can burn a lot of energy, and treatment side effects may mean you eat less or lose your appetite.

During active treatment, try to maintain your weight to help you stay strong and recover faster. To help avoid weight loss or to maintain your weight, eat more protein, fat and carbohydrates to increase your energy (kilojoules/calories). This approach is usually temporary to help you keep eating during and after treatment.

How to manage weight loss
  • Treat food like medicine: something you have to have. Set times for meals and snacks rather than waiting until you’re hungry.
  • Carry snacks such as hard-boiled eggs, muesli bars, dried fruit and nuts, crackers and fruit buns.
  • Try ready-to-use drinks if travelling or if preparation is difficult. Examples include Sustagen, Ensure, and Resource Fruit Beverage. See more information on food-type nutritional supplements.
  • Choose nourishing and higher kilojoule (calorie) fluids or snacks, for example, drink milk rather than water and choose cheese and biscuits over lollies.
  • Include high-energy and high-protein foods at every meal or snack.
Ways to add energy and protein
What to add Meals and snacks
full-cream milk, cream or coconut milk porridge, sauces, desserts, mashed vegetables, egg dishes, cream soups, scrambled eggs, milkshakes
yoghurt or sour cream dips, salad dressings, fruit, potatoes, soups
butter, margarine or olive oil bread, toast, mashed potato, cooked vegetables, rice, pasta
cheese (e.g. cheddar, ricotta, fetta, haloumi, cream cheese) scrambled eggs, sauces, soups, vegetables, casseroles, salads, toast, sandwich fillings, pasta sauce, crackers
mayonnaise egg or chicken sandwiches, potato salad, coleslaw, salad dressing
peanut butter bread, toast, porridge, crackers, pancakes, scones, fruit, smoothies
avocado toast, sandwich fillings, dips, salads, crackers, smoothies
nuts and seeds porridge, muesli, yoghurt, salads, baked goods, stir-fries, desserts
egg toast, sandwich fillings, stir-fries, mashed potato, soups, pasta sauce, salads
Weight gain

Although it is more common to lose weight during treatment, some people gain weight. This can happen for various reasons.

  • Some chemotherapy drugs and steroid medicines can cause your body to retain extra fluid in cells and tissues. This is called oedema, and makes you feel and look puffy.
  • Hormone therapy lowers the amount of hormones in the body, which slows your metabolism.
  • Steroid therapy can increase abdomen size, cause fluid retention and lead to a rounded, puffy face.
  • Feeling stressed or upset can also make some people eat more.
  • Being tired because of the treatment may mean you exercise less.

If you gain weight during treatment and are concerned, speak to your doctor or dietitian about how to best manage it.

Food-type nutritional supplements

If treatment side effects mean you cannot eat a balanced diet, or you are losing weight without trying, food-type nutritional supplements can increase nutrient intake. They are used as snacks between meals.

Many pharmacies and supermarkets sell these specially formulated nutritional supplements. You do not need a prescription from your doctor or dietitian to buy them.

If you are having trouble swallowing, talk to a speech pathologist for directions on thickening the supplement.

Types of food-type nutritional supplements

There are many different types of food-type nutritional supplements, including:

Oral supplements

Most are powder-based and often come in different flavours. There are many types to suit different nutrition needs, for example, high fibre, low lactose or low glycaemic index. You can sprinkle it on food or stir it through drinks or meals. Examples include Enprocal, Ensure, Fortisip, Proform and Sustagen Hospital Formula.

Liquid supplements

Most are milk-based and often come ready-to-drink. They are available in different flavours and can be low in lactose, gluten free or have a low glycaemic index. Examples include Ensure Plus, Resource Plus, Resource Protein, Resource 2.0, and Sustagen Ready To Drink.

Some liquid supplements come as a clear fluid and these are often fruit flavoured. They can be a good choice if lactose-free or low-fat supplements are needed. Examples include Enlive Plus, Fortijuice, and Resource Fruit Beverage.

Food-type supplements

These are available as different- flavoured soups, custards, jellies, puddings and dessert powders.

Make your own nutritional supplement to add to food and drinks using the enriched milk recipe.

Vitamin and mineral supplements

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 the body absorbs them better. If you are able to eat a variety of foods, you usually won’t need to take vitamin and mineral supplements.

Many vitamin and mineral supplements contain levels of antioxidants (such as vitamins C and E) that are much higher than the average amount of nutrients needed each day for optimal health. These are called Nutrient Reference Values. More research is needed to determine the impact of using antioxidants and other vitamin supplements during chemotherapy or radiotherapy treatment. It’s best for people having these cancer treatments to avoid vitamin and mineral supplements, except to treat a known deficiency of a certain nutrient.

Using high doses of vitamins

Some people believe that taking high doses of certain vitamins will strengthen the body’s immune system during cancer treatment. However, there is little evidence to support this claim. In fact, many vitamins and mineral compounds can be toxic at high levels, and may affect how chemotherapy, radiotherapy and other medicines work.

If your appetite is poor, check with your doctor or dietitian before taking any vitamin or mineral supplements.

Your feelings about eating problems

Changes to the way you eat may make you feel anxious, particularly when you know eating well is important. If you can’t eat much because of treatment side effects, you may be worried about upsetting people who have prepared food for you. These strategies may help you cope.

Try relaxation and meditation exercises

Both of these strategies can help you feel calm and less stressed. There are many self-help CDs, DVDs and smartphone apps that will guide you through these different techniques.

Be active every day

Studies show that people feel better when they do some exercise each day. It can also help improve your appetite and manage your weight.

Join a cancer support group

Talking to people who have been in a similar situation to you may make you feel less isolated and provide you with practical strategies. Cancer Council can link you with others by phone, in person or online. Call 13 11 20 to find out more.

Talk to someone about the way you’re feeling

Some people find it useful to talk to someone who is not their partner, family member or friend. You may choose to speak to a social worker, psychologist, nurse or your doctor or call Cancer Council 13 11 20.

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