Weight Changes


The shock of a breast cancer diagnosis, the disruption of your life, getting through and beyond treatment, the strain of relationships at home and at work, financial stress, and less physical activity all can contribute to weight gain or loss during treatment. While it’s more common for people to gain weight during and after treatment, some people lose weight.

Gaining or losing a few pounds is normal, but a considerable weight change — say 5% to 10% of your total body weight — could have an effect on your health.

Breast cancer treatments that are associated with weight gain or loss:

  • Ixempra (chemical name: ixabepilone), a chemotherapy medicine
  • hormonal therapy:
    • Arimidex (chemical name: anastrozole) 
    • Aromasin (chemical name: exemestane)
    • Evista (chemical name: raloxifene)
    • Fareston (chemical name: toremifene)
    • Faslodex (chemical name: fulvestrant)
    • Femara (chemical name: letrozole)
    • tamoxifen
  • Avastin (chemical name: bevacizumab), a targeted therapy

Other medicines you may be taking during treatment, including pain medications, anticonvulsants, bisphosphonates (bone-strengthening medicines), and steroids also can contribute to weight gain or weight loss.

Managing weight changes

If you’re concerned you’ve gained or lost too much weight, talk to your doctor. Together, you can figure out a healthy weight for you and develop a plan for eating and exercising to help you reach it. You also may want to talk to a registered dietitian if you’d like more detailed information about nutrition during breast cancer treatment. You can get a list of dietitians in your ZIP code at the Academy of Nutrition and Dietetics website.

Managing weight gain

  • Eat a healthy diet full of vegetables, fruits, and whole grains.
  • Limit saturated fat, salt, sugar, and alcohol to reduce calories.
  • Get moving. Exercise is now considered such an important part of daily life that it was added to the U.S. government’s guide to healthy eating. Aim for 3 to 5 hours a week of moderate exercise (walking at an average pace).

Visit the Breastcancer.org Eating to Lose Weight After Treatment pages in the Nutrition section for more tips.

Managing weight loss

  • Try to eat small meals or snacks every hour to make sure you’re getting enough calories.
  • Snack on foods high in protein but low in fat, such as yogurt and cottage cheese, lean meat or fish, and lentils.
  • Use low-fat milk in some recipes instead of water.

Visit the Breastcancer.org Eating to Maintain or Gain Weight After Treatment pages in the Nutrition section for more tips.

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