Weight gain after cancer treatment

For many people, a cancer diagnosis and cancer treatment can make it hard to have a healthy lifestyle. People do not usually expect to gain weight during cancer treatment. But some treatments, side effects or even lifestyle changes can cause you to gain weight:

Do not be too upset if you find you have gained weight. Sometimes knowing why it has happened can help you think of ways to manage it. If you think you have gained weight because you are depressed, talk to your GP or nurse. There are treatments for depression, such as counselling and antidepressants.

If you are having hormonal therapy as part of your treatment, it is important to keep taking it, even if you think it is causing weight gain. Talk to your cancer doctor or nurse if you are worried about this. Eating healthily and being more physically active can help you manage your weight.

If cancer or its treatment causes your weight to change, your clothes may no longer fit. The cost of buying new clothes can be worrying for some people. If you are worried about money, call the Macmillan Support Line on 0808 808 00 00 for information and advice. We have more information about getting financial help.

Before trying to lose weight, it is important to speak to your GP, cancer doctor or nurse. They can talk to you about the right way for you to lose weight. They do this by looking at the type of cancer you have and your treatment. They will also ask about your weight before the cancer diagnosis, and any other medical conditions you have.

Your doctor or nurse will measure your body mass index (BMI) to see if you are a healthy weight for your height. They may check other things, such as your waist measurement and blood pressure. You may also have a blood test to check for health conditions that may cause weight gain.

They may suggest you talk to other health professionals, such as:

• a dietitian, for advice about your diet
• a physiotherapist, for exercises to help improve your fitness
• a specialist nurse, for advice and support about managing weight gain.

Your doctor or nurse may also give you information about where you can get help and support in your local area.

Body mass index (BMI) is a way of measuring if you are a healthy weight for your height. Your GP or nurse will work out your BMI for you. There is also a BMI calculator on the NHS website.

Your BMI score shows which weight category you are in:

• A BMI of less than 18.5 is underweight.
• A BMI between 18.5 and 24.9 is a healthy weight.
• A BMI between 25 and 29.9 is overweight.
• A BMI of 30 and over is obese (well above the healthy weight range for your height).
• A BMI over 40 is very obese.

BMI scores are different for older people, some ethnic groups and people who are very muscular. Talk to your doctor or nurse about your BMI before you start trying to lose weight. They can help you set a target weight that is healthy for you.

You can use the chart below to work out your BMI. Find the line that matches your weight and follow it until it crosses the line that matches your height. Talk to your GP or nurse if you are below or above the healthy range.

Your waist measurement can also be used to see if you are a healthy weight. People who have more fat around their waist have a higher risk of health problems. To measure your waist, wrap a tape measure around your waist (like a belt). You should do this halfway between your lowest rib and the top of your hip bone.

A healthy waist measurement for:

• women is less than 80cm (31½ inches)
• men of South Asian origin is less than 90cm (35 inches)
• men not of South Asian origin is less than 94cm (37 inches).

Doing more physical activity is another positive lifestyle change you can make. Being active helps you burn off energy (calories) from food. This can help you lose weight and make you feel healthier. Even if you do not lose weight, being more active can boost your immune system. It can also help you recover from treatment side effects. Together with eating a healthy diet, it can help reduce the risk of some cancers coming back.

Being physically active can mean doing activities like walking or gardening. Or it can mean more energetic activities, such as running, cycling or going to the gym. Any increase in physical activity is good for your health and will help you burn more energy (calories).

If you have problems with walking or balance, your doctor may refer you to a physiotherapist. They can assess you and show you how to exercise safely. Some doctors may be able to refer you to an exercise programme run by fitness trainers in your area.

If you want more information about exercise you can download our booklet about Physical activity and cancer. We also have information on our website about physical activity during and after cancer treatment.

The NHS has useful tools, including how to move more, eat well and be healthier. You can also download them as free apps using your mobile phone or tablet.

Weight gain can be upsetting and difficult to cope with. This is because it can be a visible reminder of your illness. It can also affect your body image. Body image is the picture you have in your mind of how you look. It is how we think and feel about our bodies and how we believe others see us.

If you gain weight because of cancer or its treatment, you will see a different image of yourself from the one you are used to. You may find it hard to accept that you look different because you have gained weight. You may feel angry, anxious or sad. It is natural to feel like this. It is part of adapting to the way you see yourself. You may meet other people who have similar thoughts and feelings.

You may worry that the change in your appearance will affect relationships with a partner, family and friends. You may be anxious about what people think of you or about being rejected. Or you may feel self-conscious about eating at home or out with your family and friends.

People often keep their thoughts and feelings about their bodies to themselves. But keeping your worries hidden can make them grow into something bigger. So, it is important to talk to someone.

Many people find it helps to talk to someone close to them. If you find it difficult to talk about your feelings with a partner, family member or a friend, you could talk to your doctor or specialist nurse. You may also find it helpful to speak to a counsellor. Your GP or nurse can give you advice on how to contact one.

If you are close to someone who has had physical changes, it may take you time to adjust and accept the changes. You may need to talk about your feelings too.