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Breast cancer and weight gain

After breast cancer treatment some women find that they have gained weight. We explore the causes and how health professionals can help.

Author: Rachel Clark
Published: 2 November 2022

Weight gain after breast cancer treatment can happen for a number of reasons:

  • Chemotherapy (using anti-cancer drugs to destroy cancer cells) and other treatments can bring on the menopause and weight gain is a symptom of this.
  • Steroids cause weight gain and are often given with chemotherapy.
  • Hormonal therapy, which is usually given for a number of years, can also cause
    weight gain. Hormonal therapy drugs work by altering the production or activity of particular hormones in the body.
  • During treatment, women are less likely to be active.

If a woman is having hormonal therapy as part of their treatment, it is important they keep taking it, even if they think it is causing weight gain. They should talk to their cancer doctor or nurse if they are worried about this.

Eating healthily and being more physically active can help people manage their weight.

Before trying to lose weight, it is important that women speak to their GP, cancer doctor or nurse. They will look at the type of cancer they have and their treatment. They will also ask about their weight before the cancer diagnosis, and any other medical conditions they have. They may check other things, such as waist measurement, blood pressure and blood tests to check for health conditions that may cause weight gain.

They may also suggest that women talk to other health professionals, such as:

Nutritional tips

People may find it helpful to:

  • Eat plenty of vegetables, fruits, legumes and whole grains. The dietary fibre will help them to feel full longer.
  • Make sure they have a well-balanced diet with plenty of low-fat protein foods such as fish, chicken, eggs and beans.
  • Choose reduced-fat products, such as low-fat or semi-skimmed milk and low-fat yogurt.
  • Choose water, sugar-free squash, and coffee and tea without sugar instead of sugary drinks.
  • Make sure they eat regularly throughout the day and reduce portion sizes.
  • Sit down when they eat and take time to enjoy their meals. This may help to recognise feelings of fullness which can prevent overeating.
  • Exercise for at least 30 minutes daily. Finding an activity they enjoy will make it easier to be active.
  • Cut down on or avoid alcohol.

Useful links for your patients and clients

This article is from Informed, our regular newsletter for health professionals. Sign up for Informed and a host of other resources here.

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