1. Weight changes after breast cancer treatment
2. How can I lose weight after breast cancer treatment?
3. How can I put on weight after breast cancer treatment?
4. Bone health after breast cancer treatment
5. Vitamins and supplements during and after breast cancer treatment

1. Weight changes after breast cancer treatment

After treatment for breast cancer, you may have gained or lost weight.

It can be helpful to speak with your GP or practice nurse. They can assess if your current weight is healthy. To do this they will measure your weight and height to calculate your body mass index (BMI).

If your BMI is too high or low, they can help you put a plan together. They may refer you to a dietitian if they think this would be helpful. They can also let you know about any local schemes aimed at helping people manage their weight and be more active.

Find out more about diet and breast cancer.

2. How can I lose weight after breast cancer treatment?

We usually put on weight when the amount of calories we eat is more than the amount of calories we burn through normal everyday activities and exercise.

Some people put on weight during and after treatment, which can be upsetting. This may be due to:

  • The side effects of some drugs, which can increase appetite
  • The body retaining fluid
  • Being less active than usual
  • Overeating when you’re anxious or because your usual routine has changed
  • The menopause (as a result of your treatment)

How to lose weight safely

If you need to lose weight after treatment, aim for a realistic weight loss of about 0.5–1kg (1–2 pounds) a week.

The only way to lose weight healthily and keep it off is to make some permanent changes to the way you eat and exercise. Try to:

  • Reduce your portion sizes – using a smaller plate can help
  • Eat at least five portions of fruit and vegetables a day
  • Choose wholegrain varieties of bread, pasta and cereals
  • Use lower-fat dairy foods, such as skimmed or semi-skimmed milk or lower-fat cheese such as feta, reduced-fat cheddar or cottage cheese
  • Go for lean cuts of meat and trim off as much fat as possible
  • Include beans and pulses in your diet
  • Limit the amount of alcohol you drink
  • Limit the amount of biscuits, cakes, chocolate and crisps
  • Choose healthier options when eating out and remember that takeaways can be high in fat and calories

Some people find the support from a local weight loss scheme or club helpful.

As well as eating a healthy diet, you should also try to do some regular moderate-intensity exercise.

The NHS has developed a 12-week weight loss programme in association with the British Dietetic Association. Your GP can tell you more about this or you can download the guide from the NHS website.

Some pharmacies offer a free weight management service to assess your weight and give you appropriate advice and support.

3. How can I put on weight after breast cancer treatment?

If you’ve lost weight during your treatment, some simple changes to your diet can help.

To put on weight in a healthy way, you need to eat more calories and more protein. Aim to eat three meals and some snacks throughout the day, based on the Eatwell Guide. Have more of the protein-rich foods like lean cuts of meat, fish, eggs, nuts, seeds and pulses (such as lentils and beans). Also include healthy fats such as avocados, olive or rapeseed oil, and unsalted peanut butter. Adding milk powder or protein powder to drinks or food may also help.

Your GP can prescribe high-protein or high-energy drinks and soups if you need extra help to gain weight, or they may refer you to a dietitian.

4. Bone health after breast cancer treatment

For some people, treatments such as chemotherapy or hormone therapy can affect bone health. This can increase the risk of osteopenia or osteoporosis, conditions that affect the bones.

It’s important to get enough calcium from your diet as calcium is vital for healthy bones.

Find out more about looking after your bones during and after treatment.

5. Vitamins and supplements during and after breast cancer treatment

If you’re finding it difficult to get essential nutrients or vitamins from your diet alone during or after treatment, your GP may prescribe a dietary supplement. For example, if your bone health has been affected they may prescribe a calcium or vitamin D supplement.

However, unless you’re having problems recovering from treatment, supplements are not needed.

Some people wonder whether certain herbal products might help, for example with the side effects of treatment. However, there’s conflicting evidence about the safety or effectiveness of some herbal products, and some may affect how certain cancer treatments work. Talk to your specialist, GP or a dietitian before taking them. 

Find out more about herbal medicines.

Last reviewed: January 2020
Next planned review begins 2022

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