As research by Macmillan Cancer Support suggests friends and family can encourage people with cancer to do more exercise, we look at some of the things you can do to help you lose weight if you've put it on during breast cancer treatment.

A gentle walk

We often hear on the Helpline from people worried that they’ve put on weight during and after breast cancer treatment.

This can happen for several reasons. For example some drugs can increase your appetite you may be less active than usual when having treatment or you may eat more than usual if you’re anxious.

Whatever the reason putting on weight can be a distressing effect of treatment and one that you may not have been expecting. It can affect how you feel about your body and leave you with low self-esteem.

Variety of foods

One of the ways to start losing weight is to eat a healthy balanced diet by eating a variety of foods from each of the four main food groups every day.

Fatty and sugary foods and drinks are not a main food group and it will help with weight loss to cut right back on them; drink alcohol only in moderation.

Unless you’re having problems recovering from treatment you shouldn’t need supplements such as iron or multivitamins. Supplements can do harm as well as good so talk to a dietitian or your specialist before you take any.


Regularly drinking more than the recommended maximum amount of alcohol may increase the risk of breast cancer recurrence. Drinking in moderation (one to two units of alcohol a day) is not thought to be harmful. One unit of alcohol is equal to half a pint of beer one 125ml glass of wine or a single 25ml measure of spirits.

Getting active

Another way to help with weight loss is being physically active during and after treatment but this can be difficult especially if you have side effects such as fatigue or you feel unwell.

Regular physical activity has many benefits and there’s evidence that being active and maintaining a healthy weight after treatment can reduce the risk of breast cancer coming back.

Before you start any exercise discuss it with your GP (local doctor) or breast care nurse and then begin gently and build up gradually. If you’ve had reconstructive surgery check with your specialist team when you can start exercising.

The best exercise is one that makes your heart beat faster. You’ll feel warmer and breathe slightly harder but you should still be able to hold a conversation. Picking an activity that you enjoy will help you stick with it.

Physical activity and lymphoedema

It’s thought that exercise doesn’t cause or worsen lymphoedema and may even reduce symptoms. The type of activity best for you depends on the severity and cause of your lymphoedema and whether you have any other medical conditions.

Wear any compression garments you’ve been given while exercising as they help increase lymph and blood flow. Always stop if your arm gets tired.

If you’re facing issues not covered here or just want further details there’s lots more about diet and breast cancer in our information section.