Tamoxifen and weight gain

I have been on tamoxifen following surgery, chemotherapy and radiation for stage II breast cancer.  Even though I exercise regularly and watch what I eat, I have been gaining weight and wonder if it is due to the tamoxifen or having been thrust into chemical menopause from the treatments.

[CCF-RN,MSN-JS]

Dear Artygal, Both factors could have some contribution to the weight gain you are experiencing.  Whether menopause occurs naturally or is chemically induced, similar processes and effects occur. Changes in body fat distribution, as well as metabolism occur, which make gaining weight easier.   This does not mean that it is inevitable that women gain weight.  However, the physical activity and diet that may have been satisfactory in keeping weight off in the past may not be enough with these changes.  You may need to make some adjustments in your regimen.  You can find many variations on what to do but the basics are a lifestyle incorporating increased physical activity, and low-fat, reduced calorie diet.