Weight changes can be common during cancer treatment. Some people gain weight, while others lose weight. Mostly, it is best to try to stay the same weight you were before you had cancer to help your strength, recovery and treatment.

Managing changes in your weight

Weight changes can be common during cancer treatment. Some people gain weight, while others lose weight. Mostly, it is best to try to stay the same weight you were before you had cancer to help your strength, recovery and treatment.

Weight gain

Some people gain weight due to some chemotherapy medications, steroids, hormone therapy, being less active, eating more and/or retaining fluid.

A small increase in weight is not usually a problem. But a large weight gain can affect your general health. It can increase your blood pressure and your risk of developing diabetes and heart problems. Weight increases can affect how you feel about yourself, your confidence, and energy levels.

  • There are a number of reasons you may put on weight during cancer treatment:
  • fatigue or tiredness is a common side effect of chemotherapy. This can lead to you being less active.
  • treatment may cause fluid retention (oedema) that can also increase your weight
  • chemotherapy can also cause menopause for some women. This means a lowered metabolism (the rate at which your body uses energy)
  • during treatment you may crave less healthy food
  • if you are having steroids as part of your treatment the side effects may include an increase in appetite and, longer term, can lead to a build-up of fatty tissue
  • hormone therapy involves medicines that lower the amount of oestrogen and/or progesterone in women, and testosterone in men. Changes in hormone levels can lead to increased fatty tissue, a reduction in muscle mass, and slower metabolism
  • people with cancer sometimes eat more to make themselves feel better during treatment. Over time, this can result in weight gain.
  • most treatment can mean you are less active than usual over a longer period of time, often causing weight gain.

Losing weight is not easy and can take time. Don’t be hard on yourself - try to set realistic goals through healthy eating and keeping active.

Get family/whānau and friends to support you.

Tips for losing weight

Talk to your treatment team about safe ways to lose weight. Avoid fad diets or medications promising rapid weight loss. You’re more likely to keep weight off if you lose it slowly and steadily.

Things you can do include:

  • Follow the healthy eating tips
  • Try to have smaller meals - use a smaller plate and avoid going back for seconds.
    Choose whole grain bread, pasta and cereals – these contain increased fibre which can make you feel fuller for longer.
  • Try to eat plenty of fruit and vegetables which are filling but not too high in calories.
  • Limit fat, sugar, and white flour. Swap biscuits, cakes and sweets for unsweetened and unsalted options. Snack on fruit and vegetable sticks rather than biscuits, cake and sweets.
  • Drink water instead of soft drinks, and unsweetened tea or coffee with low fat milk.
  • Avoid or limit alcohol as it is high in calories.
  • Try healthier ways of cooking such as steaming or BBQ instead of frying.
  • Limit the amount of takeaways you eat as they are usually high in fat and salt.
  • Increase your activity – always start slowly and build up gradually.

If you are concerned about your weight gain, speak to your treatment team for help in managing this.

Call your doctor if you experience any of the following signs of fluid retention:

  • if your skin feels stiff or small indents are left after pressing on the swollen area
  • if you have swelling in your arms or legs, especially around the ankles and wrists
  • if rings, watches, bracelets, or shoes are tighter than usual
  • if your hands, elbows, wrists, fingers, or legs are less easy to move.

Weight loss

The side effects of cancer and its treatments can make it hard to maintain your weight.

Eating small frequent meals high in energy (calories), fat, carbohydrates and protein may help you maintain a stable weight.

High protein foods

  • Meat, fish, chicken, and eggs
  • Tofu, legumes, lentils, and hummus
  • Nuts and nut butters
  • Milk and soy milk (oat, nut, rice and coconut milks are lower in protein)
  • Cheese and yoghurt
  • Nutritious drinks: milkshakes, smoothies or supplement drinks (like Complan, Fortisip, Ensure, and Sustagen)
High energy foods
  • Oils, margarine, butter, avocado, mayonnaise, cream, sour and cream cheese
  • Baking such as cake, muffins, scones/pikelets, jam and cream
  • Desserts such as rice and custard puddings, ice cream and jelly, instant pudding, and yoghurt
  • Fruit juice and soft drinks
Ways to boost your calorie and protein intake
  • Use high fat milks, blue or silver top
  • Add extra milk powder to milk (enriched milk: mix 3 tablespoons of powder with 500 mililitres of milk)
  • Add extra margarine, avocado, oil, sour cream or grated cheese to bread, rice, pasta, vegetables, savoury dishes and soup
  • Cook food in oil or a little butter and add extra on the top
  • Add a little cream to cereals, stewed fruits, desserts, baking, soups or drinks
  • Snack on yoghurt, custard, ice-cream, milk puddings, stewed fruit, baking, dried fruit and nuts
    Eat bread or toast, pita bread, crumpets or crackers with margarine, pâté, chutney, cheese, hummus, nut butters, avocado, jam and honey
  • Choose nutritious fluids: milk milo, milkshakes, fruit smoothies, juice and supplement drinks

If you have tried increasing your calorie intake but are still struggling to eat enough, you may benefit from a nutritional supplement drink.

Talk with a dietitian or your treatment team to get the right drinks for your needs such as:

  • powdered drinks: Complan, Ensure, or Fortisip
  • ready-to-drink liquids: Ensure Plus, Fortisip, Fortisip Multi Fibre, or Ensure TwoCal HN
  • fortified fruit juices: Fortijuce, Ensure Plus juice, or Recover Calogen (fat only and can only be used in certain situations)

Some supplement drinks are available in supermarkets and others from pharmacies. You may be able to get a Special Authority number and prescription for supplements at minimal cost, after an assessment by your treatment team.

If your nutritional needs are unable to be met, your treatment team may suggest a feeding tube.

A feeding tube can be used short or long term, to supplement your meals or be your complete source of food and fluid. It is a way to ensure that your body gets the nutrition you need while you are having treatment.

Feeding tubes can be managed at home with support and guidance from your treatment team.

Last updated: December 22, 2022