Sex hormones and weight changes in women
Some cancer treatments lower the amount of sex hormones in the body. Low levels of sex hormones can sometimes make you put on weight.
What are the sex hormones?
Hormones are natural substances made by the glands of our hormone (endocrine) system. They are carried around our body in our bloodstream. The main female sex hormones are oestrogen and progesterone. The main male sex hormone is testosterone.
Sex hormones and weight changes
After the 
the way that fat is distributed around the body changes. Extra weight tends to build up around the waist, rather than on the hips and buttocks. This change is caused by a drop in oestrogen levels.
But weight gain is usually caused by a combination of factors, including diet and exercise. You might notice a change in your body shape if treatment for cancer has put you into the menopause. Or if the treatment blocks the action of oestrogen.
Coping with weight changes
Changes in weight can affect your confidence and self esteem. Trying to make changes to your diet and starting or increasing exercise when you aren’t feeling at your best can be difficult.
Treatments for cancer, including hormone treatments, can cause tiredness which may make exercising more difficult. And this can add to weight gain.
Menopausal symptoms, such as hot flushes and sweats, can also make it more difficult to cope. Talk to your doctor, dietitian, or specialist nurse about any problems you have.
Weight changes and exercise
Changing your diet and being more physically active may help you to maintain your normal weight.
Exercise
Physical activity can help to maintain muscle strength, but it needs to be a combination of aerobic and resistance exercise.
Aerobic exercise is any exercise that makes your heart and lungs work faster. It helps provide more oxygen to the muscles, for example walking or gardening.
Resistance training includes weight training and swimming. You have to use your muscles to push against the weights or water, which helps to strengthen them.
Physical activity also helps to control your weight. You don’t have to go to the gym, you can build it into your life. For example, you could get off the bus at the stop before you need to. Or do some gardening or join a walking group. Some hospitals and health centres organise exercise sessions for cancer patients. Ask your specialist nurse if this is available.
The UK government and the World Cancer Research Fund (WCRF) have suggestions to help prevent cancer and other conditions. They say that all adults should try to do at least one of the following ways of exercising:
- 150 minutes of moderate intensity activity per week; for example, 30 minutes 5 times per week
- 75 minutes of vigorous activity per week
Remember that everyone is different and exercise needs to be tailored to you. Take into account your fitness, diagnosis, and other factors that could affect safety.
Your doctor may check your cholesterol and heart health before you start an exercise plan. This is important if you have conditions such as diabetes or you are overweight.
Diet
Eating a balanced healthy diet can help you to maintain a healthy weight. It can also help you lose or put it on if you need to.
Bone health
Hormone treatment may lower your bone density, increasing the risk of fractures. Talk to your doctor if this could be a problem for you.
