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Treatment side effects and nutrition

Eating well can be a challenge when you have cancer. Sometimes it’s the cancer itself that prevents you from eating, digesting or absorbing food well. But usually it’s because of the side effects of cancer treatments.

These side effects will vary from person to person, and depend on the type of cancer, treatment and medicines you have. For some people, treatment side effects only slightly change what they can eat. For others, side effects will have a bigger impact. Most side effects that affect eating are temporary and gradually get better after treatment ends.

This information covers some of the most common impacts of cancer treatment on nutrition. It also includes practical suggestions for coping with treatment side effects and getting the nutrients you need.

Worrying about the diagnosis and treatment can also affect your appetite. If this is the case for you, talk to a family member or friend, the social worker at the hospital, your doctor or a psychologist. You can also call Cancer Council 13 11 20.

How cancer treatments can affect nutrition

TreatmentPossible side effect
surgery - removes tumour or repairs part of the bodydifficulty chewing and swallowing, reflux, diarrhoea, constipation, difficulty absorbing nutrients, weight loss, pain, fatigue
chemotherapy - drugs that kill or slow the growth of cancer cellsappetite loss, nausea, vomiting, constipation, diarrhoea, mouth sores, taste changes, lowered immunity, fatigue, weight loss
radiation therapy - the use of a controlled dose of radiation to kill or damage cancer cells; also known as radiotherapyappetite loss, fatigue, taste changes, nausea, vomiting, diarrhoea, dry mouth, difficulty chewing or swallowing, bowel obstruction, mouth sores, reflux, weight loss, pain, fatigue
hormone therapy - drugs that block the hormones that help some cancers growweight gain, appetite changes, nausea, increased cholesterol levels, constipation, mood changes
stem cell transplant - the process of replacing stem cells destroyed by high-dose chemotherapylowered immunity, sore mouth and throat, nausea, vomiting, diarrhoea, fatigue, loss of appetite, weight loss
steroid therapy - drugs used to reduce inflammation in the bodyincreased appetite, weight gain, increased risk of infection, stomach irritation, unstable blood sugar levels
targeted therapy - drugs that target specific features of cancer cells to stop the cancer growingdiarrhoea, nausea, vomiting, constipation, taste changes, mouth sores, fever, increased risk of infection, weight loss
immunotherapy - drugs that use the body’s own immune system to fight cancerdiarrhoea, bloody bowel movements, abdominal pain, bloating, weight loss or weight gain

Coping with eating issues

Changes to how much you eat may make you feel anxious. You may worry about upsetting people who have prepared your food, or you may feel self-conscious  about eating in public. It may also be hard to adjust to your changing relationship with food – for example, if you previously loved cooking and eating, but have now lost your appetite.

Be active every day – Studies show that exercising each day can help people feel better. It may also improve your appetite and help maintain a healthy weight.

Find ways to enjoy mealtimes – Take the focus off what and how much you can eat by playing music, sitting outside, lighting candles or eating with friends. This can help improve your quality of life.

Try relaxation and meditation – Relaxation and meditation exercises can help manage stress. You can use various recordings, videos, podcasts and apps to guide you through different exercises. See our ‘Finding Calm During Cancer relaxation and meditation podcast’.

Talk to someone – You may find it useful to talk to someone who is not a family member or friend. You could speak to a dietitian, social worker, psychologist, nurse or doctor, or call Cancer Council 13 11 20. Another option is to join a cancer support group. Cancer Council SA can put you in touch with others by phone, in person or online.

Common impacts of cancer treatment on nutrition

A common side effect of treatment is feeling extreme and constant tiredness. This is known as fatigue. It is different to normal tiredness because it usually doesn’t improve with rest. Fatigue can be caused by treatment side effects that reduce the number of red blood cells (anaemia) or that affect your appetite.

How to manage fatigue

  • Eat a wide variety of foods. See a dietitian for advice tailored to you.
  • Plan ahead for when you feel too tired to cook. Buy frozen meals from the supermarket or prepare food in advance and store it in the freezer.
  • Cook in the morning when you are less likely to be tired.
  • Buy groceries online instead of going to the shops.
  • Ask for and accept offers of help with shopping and cooking from others.
  • Use apps such as CanDo to coordinate offers of help.
  • Keep snacks such as wholefood muesli bars, dried fruit, nuts and wholegrain crackers in handy locations, e.g. in your bag or car. This will allow you to keep your energy levels up if you have unexpected delays.
  • Use home delivery meal companies or services that bring pre-prepared food to you. Or try companies that deliver ingredients with recipes that you can cook at home yourself.
  • Do regular exercise to help improve fatigue and appetite.
  • Eat with others to make meals as enjoyable as possible, particularly if you are feeling too tired to eat.

For more information, listen to our podcast episode on cancer fatigue and download our ‘Fatigue and Cancer’ fact sheet.

Cancer and some treatments (such as chemotherapy and stem cell transplants) can reduce your white blood cell level, making it harder for your body to fight infections. If this happens, you will need to take care preparing and storing food because you are more likely to get foodborne illnesses.

General precautions

  • Wash your hands and knives, cutting boards and food preparation areas thoroughly with hot soapy water before and after cooking.
  • Take extra care when eating out. Where possible, ask for meals to be made fresh and avoid pre-prepared foods that have been sitting for unknown periods of time.

Making safer food choices


  • cook thoroughly
  • thaw in refrigerator or microwave and cook immediately

Precautions to take

  • refrigerate leftover cooked chicken immediately – don’t let it cool on the benchtop
  • eat within 24 hours; reheat until steaming hot
  • don’t refreeze raw chicken after defrosting
  • don’t buy ready-to-eat chicken


  • cook thoroughly
  • thaw in refrigerator or microwave

Precautions to take

  • refrigerate leftover cooked meat immediately – don’t let it cool on the benchtop
  • eat within 24 hours; reheat until steaming hot
  • don’t refreeze raw meat after defrosting


  • cook thoroughly
  • buy fresh seafood

Precautions to take

  • refrigerate leftover seafood immediately, and eat within 24 hours
  • avoid raw seafood (e.g. oysters, sushi) and ready-to-eat peeled prawns
  • don’t buy ready-to-eat smoked seafood

Cold meats

  • store home-cooked cold meats in fridge

Precautions to take

  • avoid ready-to-eat cold meats from the deli counter and packaged, sliced ready-to-eat cold meats


  • eat freshly made

Precautions to take

  • avoid pre-made sandwiches

Salad, fruit and vegetables

  • wash thoroughly before preparing

Precautions to take

  • refrigerate leftovers immediately, and eat within 24 hours
  • avoid ready-to-eat or pre-packaged deli salads (including pre-cut fruit salads and roast vegetables)
  •  pick unblemished fruit and vegetables


  • keep uncracked, clean eggs in fridge
  • cook until yolks and whites are solid

Precautions to take

  • avoid cracked, dirty and raw eggs
  • avoid food containing raw eggs (e.g. homemade mayonnaise, raw cake mix and biscuit dough)

Cheese and other dairy products

  • eat hard or processed cheese
  • store cheese and pasteurised dairy products in fridge

Precautions to take

  • avoid soft, semisoft and surface ripened cheeses (e.g. camembert, brie, ricotta, feta, blue)
  • avoid unpasteurised dairy products

Packaged food

  • eat within use-by dates

Precautions to take

  • store unused perishable food in fridge in clean, sealed containers, and use within 24 hours of opening


  • keep frozen

Precautions to take

  • avoid soft serve ice-cream

Not feeling like eating is known as loss of appetite. This may happen because of the side effects of cancer itself or the treatment, such as feeling sick, not enjoying the smell of food, or worrying about the diagnosis and treatment. Loss of appetite can contribute to weight loss and malnutrition. It is important to keep trying to eat so you can maintain your weight and meet your nutrition needs.

How to manage loss of appetite

  • Eat small meals every 2–3 hours during the day, and keep to a regular eating pattern rather than waiting until you’re hungry.
  • Follow your appetite. It’s okay to eat what you feel like, when you feel like it, e.g. have cereal for dinner or a main meal at lunchtime. Putting on or maintaining your weight is the main focus at the moment.
  • Exercise before a meal. Gentle physical activity can make you feel hungry, e.g. take a short walk around the block.
  • Use a smaller plate. A big plate of food may put you off eating.
  • Add extra energy to your food with butter, cream, cheese and sour cream.
  • Choose fluids that are high in kilojoules and protein, such as milk, milkshakes, smoothies or creamy soup. These may be easier to manage than a meal.
  • Make mealtimes more enjoyable by setting the table, playing music or eating with someone.
  • Manage side effects that may be affecting your appetite.

Some cancers, treatments and medicines can cause stomach contents to come back up into the oesophagus (food pipe). This is known as reflux, and  it can irritate the lining of the oesophagus. Reflux can lead to a burning feeling in the upper chest, oesophagus and/or throat. This sensation is called indigestion or heartburn. Eating certain foods or lying down after eating can make heartburn worse.

Heartburn may make you feel too uncomfortable to eat much, which could lead to weight loss. Keeping a diary of the foods you eat and your  symptoms can help you identify which foods trigger the heartburn. If the tips below don’t relieve heartburn, let your doctor know. They may be able to prescribe medicines to help.

How to manage reflux

  • Avoid large meals; try to eat three small meals and three snacks throughout the day.
  • Eat slowly and enjoy your meal. Avoid wearing tight clothing (especially belts) while eating.
  • Sip fluids between meals, rather than drinking large amounts at mealtimes.
  • Limit or avoid foods that may make heartburn worse – very spicy foods, high-fat foods (e.g. fried food, pastries, cream), acidic foods including tomato and tomato products, citrus fruits, vinegar, chocolate, coffee (including decaf), strong tea, soft drinks and alcohol.
  • After eating, sit upright for at least 30 minutes and avoid lying down or activities that involve bending over (e.g. gardening).
  • Sleep with the head of the bed lifted by 15–20 cm. Put blocks under the front bed legs or use a wedge under the mattress.

Some treatments can affect the taste and smell of foods. Chemotherapy and targeted therapy drugs can change the taste receptors in the mouth. Radiation therapy or surgery to the head, neck and mouth area can damage the salivary glands and tastebuds on the tongue. Food may taste bitter  or metallic, or may not have as much flavour as before.

It’s common to have changes in taste during treatment and for a short time afterwards. People with cancer often say, “All food tastes the same”,  “Food tastes like cardboard”, “Food tastes metallic”, or “I no longer like the taste of my favourite food”. It may take several months for your sense of taste to return to normal. In some cases, taste changes may be permanent.

Some people find that even the taste of water is a problem. This can make it challenging to get through the recommended amount of water each day and to swallow medicines with water. Adding lemon, lime, fruit juice, cordial or fresh mint to water may make it easier to drink.

A sore mouth, sore throat or swallowing difficulties can make it hard to eat. Talk to your doctor, speech pathologist, dentist or dietitian – some of the suggestions listed below may not be suitable.

How to manage changes in taste or smell

Taste changes

  • Add extra flavour to meals (e.g. fresh herbs, spices, lemon, lime, ginger, garlic, soy sauce, honey, chilli, pepper, Worcestershire sauce or pickles).
  • Keep trying different foods, as your tastes may change. You may not like bitter drinks (e.g. tea, coffee, beer, wine) or sweet foods (e.g. chocolate), even if you liked them before treatment. It is common to prefer savoury foods after treatment.
  • If meat tastes unpleasant during treatment, replace it with other protein sources (e.g. cheese, eggs, nuts, dairy foods, seafood, baked beans, lentils, chickpeas).
  • Add a little sugar to food if it tastes bitter or salty.
  • Serve food hot or warm.
  • Use bamboo cutlery if metal spoons, forks and knives taste metallic.
  • Drink through a paper or silicone straw so the taste isn’t as strong. Metal straws may add a metallic taste.

Smell changes

  • Eat cold food or food at room temperature – hot food smells stronger.
  • Consider not eating your favourite foods when having chemotherapy. Some people find afterwards that they cannot tolerate the smell of foods associated with their treatment.
  • Avoid using large amounts of strong-smelling ingredients (e.g. garlic, onion, spices).
  • If cooking smells bother you, ask others to cook, then stay out of the kitchen when food is being prepared.
  • Turn on the exhaust fan, open a window and cover pots with lids to help reduce cooking smells, or cook outside on the barbecue.
  • Avoid eating in stuffy or overly warm rooms. Have meals outside.
  • Take good care of your mouth, as a bad or bitter taste in the mouth can make things smell unpleasant.

For more information download our ‘Understanding Taste and Smell Changes’ fact sheet.

Radiation therapy to the head or neck area and surgery that affects the salivary glands can reduce the amount of saliva in your mouth, make your mouth dry or make your saliva thick and sticky. This is known as xerostomia. Without enough saliva, bacteria can grow too quickly and may cause oral thrush, which will make eating and swallowing more difficult. A dry mouth can also make it harder to keep your teeth and mouth clean, which can increase the risk of tooth decay.

How to relieve a dry mouth

  • Rinse your mouth often. Ask your doctor or nurse what type of alcohol-free mouthwash to use and how often to use it. They may give you an easy recipe for a homemade mouthwash.
  • Brush your teeth with a soft toothbrush.
  • Ask your dentist or health care team what oral (mouth) lubricants or saliva substitutes to use.
  • Avoid foods that may sting your mouth, such as crunchy or dry foods (e.g. chips, nuts, toast, dry biscuits), and salty or spicy foods.
  • Soften food by dipping it into milk, soup, tea or coffee, or moisten it with sauce, gravy, cream, custard, etc.
  • Sip fluids during meals and throughout the day.
  • Avoid smoking and limit alcohol and coffee as they remove fluids from the body.
  • Chew sugar-free gum to stimulate the flow of saliva.
  • Suck on ice cubes or frozen grapes or rub the inside of your mouth with a small amount of grapeseed oil, coconut oil or olive oil to moisten your mouth.
  • Use a moisturising lip balm to keep your lips moist.

For more information download our ‘Mouth Health and Cancer Treatment’ fact sheet.

Chewing and swallowing involve your lips, teeth, tongue and the muscles in your mouth, jaw and throat working together. Surgery to the jaw, mouth or throat areas can cause swallowing difficulties. Radiation therapy can also make chewing and swallowing hard. These changes are usually temporary, but can sometimes be permanent.

Problems chewing – People with dentures who lose weight may find their teeth become loose. Treatment for head and neck cancer sometimes involves removing teeth. Both of these things can make it hard to chew.

Difficulty swallowing – If you’re having difficulty swallowing (dysphagia), you may need to change the consistency of food by chopping, mincing, pureeing or thickening it. Signs that the texture of food is causing problems include taking longer to chew and swallow; coughing or choking while eating or drinking; feeling like food or drink is going down the wrong way; food sticking in your mouth or throat like a ball; or throat clearing after meals. A speech pathologist can assess how your swallowing is working, and a dietitian can suggest ways to make sure you are getting enough nutritious food.

Feeding tubes – Severe swallowing problems can make it hard to eat and drink. You may need a feeding tube until swallowing gets easier. This will help you meet your nutrition needs. A feeding tube is rare for most people with cancer, but is more of a possibility with cancers affecting the head and neck, stomach, oesophagus or lung. If a feeding tube is required, your treatment team will discuss this with you.

For more information download our ‘Understanding Head and Neck Cancers’ or ‘Understanding Stomach and Oesophageal Cancers’ booklets.

Ways to change the texture of foods

If you need to adjust the texture of your food, this sample menu provides some ideas. See a speech pathologist and dietitian for other options. Check with your dietitian if you have another health condition, such as diabetes, or if you have been told you need thickened fluids, as you may not be able to have all of the foods suggested here or you may need to modify them. For more information on food textures, see

Food textures

Soft and bite-sized – Food can be chewed but not necessarily bitten. It should be easily broken up with a fork and need little cutting. Sauce or gravy can be added to make it softer.

Minced and moist – Food should be soft and moist and easily form into a ball in the mouth. Small lumps can be mashed up with the tongue rather  than by biting or chewing.

Pureed – The texture of pureed food means it can be moulded, layered or piped to make it look more appealing. You can add sauce or extra liquid if you prefer.


  • Soft and bite-sized – scrambled or poached eggs; soft chopped fruit and yoghurt; oats or cereal softened with milk or yoghurt
  • Minced and moist – oatmeal porridge or wheat biscuits with lots of milk and little texture; well-cooked rice pudding; congee (rice porridge) with
    little texture
  • Pureed – strained or pureed porridge (made with milk); strained or pureed congee


  • Soft and bite-sized – boiled and mashed egg mixed with tinned tuna and store-bought mayonnaise (avoid homemade mayonnaise); baked beans
  • Minced and moist – soup with well-cooked vegetables or meat pieces (no bigger than 4 mm); well-cooked lentil dhal with very soft rice
  • Pureed – well-cooked pasta that has been pureed in a blender with added sauce; pureed tinned tuna with store-bought mayonnaise; pureed mashed potato; pureed soup strained to remove lumps


  • Soft and bite-sized – casserole with small pieces of tender meat and well-cooked vegetables; well-cooked rice or wheat noodles (not fried) with boiled vegetables and crumbled soft tofu or tender meat
  • Minced and moist – moist macaroni cheese; mashed or scrambled tofu with small, soft vegetable pieces (no bigger than 4 mm); moist risotto
  • Pureed – pureed chicken blended with extra gravy or sauce and pureed noodles; pureed lentil dhal or curry and pureed rice

Snacks, dessert and drinks

  • Soft and bite-sized – mango; stewed fruit pieces; yoghurt with soft fruit pieces; soft cake with lots of custard; fruit smoothie
  • Minced and moist – mashed banana; steamed egg pudding; soft cheesecake without the crust; semolina pudding; creamed rice; milkshake; milk or soy milk
  • Pureed – pureed pear or apple pushed through a sieve; yoghurt with no fruit pieces or lumps; ice-cream; mousse; milk or soy milk


  • Soft and bite-sized – nuts; dried fruit; dry or gristly meat; raw vegetables; muesli; hard cheeses (unless melted); hard crackers, crisps; bread, sandwiches
  • Minced and moist – nuts; hard vegetables; all bread and crackers; dried food; lollies (jubes, marshmallows)
  • Pureed – meat; eggs; cereals or vegetables that have not been pureed in a blender; peanut butter

Chemotherapy and radiation therapy can damage the cells lining the mouth and digestive tract, leading to ulcers and infections. This is known as oral mucositis. A sore can form on any soft tissue in your mouth, and make it painful to eat and swallow.

Your doctor can give you medicines to reduce pain and discomfort when you eat or drink. Some medicines can be applied directly to the mouth sores to numb them.

To reduce discomfort, eat softer foods. You may need to avoid hot, cold, salty, spicy or acidic foods and drinks. Mucositis usually gets better a few weeks or months after treatment ends.

Nausea is feeling sick and vomiting is throwing up. It’s common to have them together. Radiation therapy, chemotherapy, other medicines and the cancer itself can cause nausea and vomiting. If you have chemotherapy, you will be given anti-nausea medicine with your treatment and to take at home afterwards. In many cases, this will prevent severe nausea and vomiting, but some people do still feel sick and may vomit. It’s important to take anti-nausea medicine as directed to help prevent nausea from occurring – don’t wait until you feel sick.

Nausea and vomiting can also be triggered by stress, food smells, gas in the stomach or bowel, motion sickness or even the thought of having
treatment. After a person has had a few treatment sessions, they may link certain sights, sounds or smells with treatment and feel nauseated when they experience them. This is known as anticipatory nausea or vomiting, and it is more common in people having chemotherapy.

How to cope with nausea and vomiting


  • Have a light snack before chemotherapy, and don’t eat for a few hours after.
  • Eat small meals every 2–3 hours. Going without food for long periods can make nausea worse.
  • Choose dry or bland snacks, e.g. crackers, toast, dry cereals, bread sticks or pretzels.
  • Have cold foods or foods at room temperature as they have less aroma.
  • Drink fluids all day to avoid becoming dehydrated.
  • Try drinks and foods with ginger, e.g. ginger tea, non-alcoholic ginger beer, ginger biscuits.
  • Avoid foods that are too sweet, fatty, fried or spicy, or that have strong smells.
  • Brush teeth regularly to help reduce tastes that may make you feel nauseated.
  • Don’t eat your favourite food when feeling nauseated as you may develop a permanent dislike.


  • Take sips of fluids as often as possible, e.g. flat dry ginger ale, cold flat lemonade, weak cordial, or cold apple juice. Oral rehydration solutions, such
    as Hydralyte or Gastrolyte, can help keep you hydrated.
  • See your doctor if vomiting lasts for more than a day or if you can’t keep fluids down, as you may become dehydrated.
  • Slowly introduce more nourishing fluids once you stop vomiting, e.g. cold or iced drinks; milk or fruit drinks with added water so they are not too strong; clear broth; weak tea.
  • Have small amounts of solid foods once vomiting is under control, e.g. plain dry biscuits; toast or bread; stewed fruits and yoghurt.
  • Increase how much you eat until you’re eating what is normal for you.
  • Listen to our podcast episode on appetite loss and nausea.

Constipation is when your bowel movements (faeces, stools or poo) are hard and difficult to pass. It can be caused by different factors including: some chemotherapy and anti-nausea drugs; strong pain medicines (opioids); eating less fibre; not moving around as much; not drinking enough (dehydration); or not eating enough.

If you have severe constipation with symptoms such as abdominal (tummy) pain and swelling, nausea and vomiting, this may be sign of a blockage in the bowel (bowel obstruction). This needs urgent medical attention.

How to manage constipation

  • Drink 8–10 glasses of fluid a day (e.g. water, herbal tea, milk-based drinks, soup, prune juice) to soften faeces.
  • Eat foods high in insoluble fibre (e.g. wholegrain breads, cereals or pasta; raw and unpeeled fruits and vegetables; nuts and seeds; legumes and pulses).
  • If you add foods with more insoluble fibre to your diet, drink more fluids to avoid the extra fibre making constipation worse.
  • Ask your doctor about using a laxative, stool softener and/or fibre supplement.
  • Plan to do some physical activity every day. Ask your doctor, exercise physiologist or physiotherapist about the amount and type of exercise that is right for you.
  • Visit your doctor if you see blood in your faeces. They’ll check for haemorrhoids or any other issues.
  • If you have had surgery for bowel cancer and have a stoma, ask your health care team for specific dietary advice. They may suggest eating more low-fibre foods to avoid constipation.

Diarrhoea is when you have loose, watery bowel movements several times a day. You may also get cramping and pain, and have an urgent need to go to the toilet. Chemotherapy, radiation therapy to the abdomen (belly) or pelvis, some types of surgery (e.g. bowel), medicines, infections, reactions to certain foods, and anxiety can all cause diarrhoea. If the tips below don’t help improve diarrhoea, ask your doctor about anti-diarrhoea medicines and rest until you feel better.

For support managing constipation and diarrhoea, visit the Continence Foundation of Australia or call their helpline on 1800 33 00 66.

How to manage diarrhoea

  • Drink plenty of water and other fluids such as diluted cordials and oral rehydration solutions (e.g. Gastrolyte) to prevent dehydration. Avoid high-sugar drinks, alcohol, strong caffeine or very hot fluids.
  • Watch for signs of dehydration such as dark yellow urine (pee) or urinating less than usual.
  • Choose foods that are low in insoluble fibre (e.g. bananas, mashed potato, white rice, white pasta, white bread, steamed chicken without skin, white fish). It may also help to eat foods that are high in soluble fibre (e.g. oats, barley, rye, legumes, peeled fruits and vegetables, avocado, soy products).
  • Avoid foods that are high in insoluble fibre (e.g. wholegrain breads, bran cereals, nuts and seeds, raw fruit, vegetable skins) and foods that increase bowel activity (e.g. spicy, fatty or oily foods, caffeine, alcohol or artificial sweeteners).
  • Switch to soy milk or lactose-free milk for a period of time. Having diarrhoea may affect your ability to digest the natural sugar in milk (lactose).

This is a group of symptoms that develops when food moves too quickly from the stomach into the small bowel. You may have cramps, nausea, racing heart, sweating, bloating, diarrhoea or dizziness.

Dumping syndrome can develop after surgery to remove part or all of the stomach (for example, gastrectomy).

The symptoms can vary depending on what you eat. Foods and drinks high in sugar such as soft drinks, juices and cordial can make dumping syndrome worse. Symptoms may begin 15–30 minutes after eating, or sometimes after several hours. They often improve over time. Your treatment team can suggest changes to what you eat and medicines to help manage dumping syndrome.

For more information download our ‘Understanding Stomach and Oesophageal Cancers’ booklet

Some chemotherapy drugs, stem cell transplants and radiation therapy to the pelvic area can make the bowel swollen and sore. This is called colitis when it affects the colon (the large bowel), and proctitis when it affects only the rectum (the last part of the bowel before the anus). You may feel the need to empty your bowels often, perhaps without much result. Straining can cause discomfort, and there may be blood or mucus in your bowel movements. Diarrhoea, nausea and vomiting are also common, but can be managed with medicines.

The small bowel may become irritated after chemotherapy or radiation therapy to the abdomen or pelvic area. This is known as enteritis and it can cause discomfort in the abdomen (like cramps or wind pain), pale and runny bowel movements, and more wind than usual.

How to manage bowel irritation

  • Eat and drink slowly, take small mouthfuls and chew your food well to avoid swallowing air.
  • Have foods low in insoluble fibre to reduce bowel irritation in the short term. Include foods high in soluble fibre to “soak up” additional liquid in your bowel.
  • Avoid fatty, spicy or fried foods, and rich gravies and sauces.
  • Reduce foods such as corn, beans, cabbage, onions, pickles and fizzy drinks, which can produce wind.
  • Drink plenty of water, and eat soft or cooked peeled fruit, fine wholemeal bread and bran to provide soft bulk. You may be encouraged to take an oral rehydration solution, such as Hydralyte or Gastrolyte, to keep hydrated.
  • Do some gentle exercise, such as walking, to encourage more regular bowel movements.
  • Tell your doctor if symptoms don’t improve. Bowel irritation is usually temporary, with colitis and proctitis lasting up to 8 weeks and enteritis lasting 1–2 weeks after treatment ends.

It’s common for people diagnosed with cancer to lose weight. This is because the process of cancer cells dividing uses up a lot of energy, and  treatment side effects can change your desire to eat, or make eating difficult or painful.

Weight loss may depend on the type of cancer you have. Losing weight without trying is a sign of malnutrition. Advanced cancer may mean the way the body absorbs food changes. This is known as cachexia. With the support of your cancer care team you can prevent or slow down weight loss.

Maintaining your weight, particularly your muscle stores, will help you stay strong and recover faster. If the tips below don’t help, talk to your dietitian about nutritional supplement drinks or having a feeding tube.

You and your family and friends may be concerned that the suggestions below are high in energy and protein. During treatment when you don’t feel well enough to eat, just eating something is more important than making healthy food choices. Keep in mind that these changes are often temporary – you can return to the usual guidelines for healthy eating once you have recovered from treatment.

Nutritional supplements

If you cannot eat a balanced diet, or are losing weight without trying, your doctor or dietitian may suggest nutritional supplements such as Sustagen, Ensure, Fortisip or Resource. These are high in energy and protein, and provide nutrients that can help maintain your strength.

Nutritional supplements are available as:

  • powders to mix with milk or water, or sprinkle on food
  • ready-made drinks, puddings, custards and jellies.

They can be used as snacks between meals, or some can be added to drinks or meals.

A dietitian can recommend the right nutritional supplement for you. If you are having difficulty swallowing, talk to a speech pathologist for directions
on thickening the supplements.

Many pharmacies and supermarkets sell nutritional supplements. While you don’t need a prescription for many supplements, a prescription may make them cheaper to buy.

How to manage weight loss

  • Treat food like medicine: something your body needs regularly to feel better.
  • Set times for meals and snacks rather than waiting until you’re hungry.
  • Have your biggest meal when you’re hungriest and not too tired.
  • Eat your favourite foods at any time of day.
  • Carry snacks so you can eat any time you feel like it. Try hard-boiled eggs, muesli bars, dried fruit and nuts, crackers and fruit buns.
  • Choose drinks and snacks that are higher in protein and energy (kilojoules), e.g. drink full-cream milk rather than water and choose cheese and  biscuits over lollies.
  • Add high-protein foods, e.g. poultry, fish, meat, eggs, tofu, dairy, nuts, seeds and legumes, to every meal or snack.
  • Add fats and oils (kilojoules) to what you are already eating, e.g. use extra butter, avocado, nut butters, cheese, extra virgin olive oil and cream. Avoid food and drinks labelled low-fat or no fat.
  • Have dessert after meals.
  • Do some gentle exercise, e.g. a walk before meals to increase your appetite.
  • Make enriched milk to use in tea and coffee, cereal, soups, sauces, scrambled eggs, milkshakes and smoothies. Add 4 or more heaped tablespoons of milk protein to 1 litre of full-cream milk and mix thoroughly. Use straightaway, or keep refrigerated and use within 24 hours (stir before use).
  • Stock up on ready-to-use nutritional supplement drinks when you are travelling or on other occasions when it is difficult to prepare a meal.

Ways to add energy and protein

Add these ingredients – full-cream cow’s milk, cream, coconut milk or soy milk (liquid or powdered versions)
to these meals and snacks – porridge, sauces, desserts, mashed vegetables, egg dishes, cream soups, scrambled eggs, congee, milkshakes, flavoured milk drinks (e.g. Milo, Akta-Vite)

Add these ingredients – yoghurt or sour cream
to these meals and snacks – dips, salad dressings, fruit, potatoes, roast vegetables, soups, rice dishes, lentil dhal

Add these ingredients – butter, margarine or olive oil
to these meals and snacks – bread, toast, mashed potato, cooked vegetables, rice and pasta dishes, soup

Add these ingredients – cheese (e.g. cheddar, cream cheese, feta, haloumi)
to these meals and snacks – scrambled eggs, sauces, soups, baked potatoes, vegetables, casseroles, salads, toast, sandwich fillings, pasta, crackers,
tacos, sauces

Add these ingredients – mayonnaise (store bought, avoid homemade)
to these meals and snacks – egg or chicken sandwiches, potato salad, coleslaw, salad dressing, tinned tuna

Add these ingredients – peanut butter, other nut butters
to these meals and snacks – bread, toast, porridge, crackers, pancakes, scones, fruit, smoothies

Add these ingredients – avocado
to these meals and snacks – toast, sandwich fillings, dips, salads, crackers, smoothies

Add these ingredients – nuts and seeds, e.g. LSA (linseed, sunflower seeds and almonds), almond meal, hemp seeds, chia seeds
to these meals and snacks – porridge, muesli, yoghurt, salads, baked goods, stir-fries, desserts

Add these ingredients – beans or legumes
to these meals and snacks – rice dishes, toast toppings, salads, pasta dishes, soups, casseroles, mince dishes

Add these ingredients – egg or tofu
to these meals and snacks – toast, sandwich fillings, stir-fries, mashed potato, soups, pasta sauce, salads

Although it is more common to lose weight during treatment, some people put on weight. This is more likely to happen with certain types of cancer such as breast cancer.

Weight gain can happen as a side effect of treatment and/or medicines:

  • Some chemotherapy drugs can cause your body to retain extra fluid in cells and tissues. This is called oedema, and it can cause weight gain and make you feel and look puffy. If chemotherapy makes you feel nauseated, you may find snacking helps but means you eat more.
  • Hormone therapy lowers the amount of hormones in the body, which slows your metabolism.
  • Steroid therapy (corticosteroids) can cause a larger abdomen, fluid retention (oedema), and a rounded, puffy face. Steroids can also increase your appetite, which may mean you eat more and put on weight.

Feeling stressed or depressed can also make some people eat differently, and being tired because of the treatment may make it harder to exercise.

If you put on weight during treatment and are concerned, speak to your doctor or dietitian about how to best manage it. It is important that your body gets enough nutrition, so do not try a weight loss diet without guidance from a health professional.

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Nutrition for People Living with Cancer

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This information is reviewed by

This information was last updated July 2022 by the following 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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