An analysis published in the Journal of the National Cancer Institute found that losing even modest amounts of weight and keeping it off was associated with lower risk of breast cancer in women 50 and over. The study pooled information on the weight of nearly 181,000 women assessed in at least three surveys over approximately 10 years. The average body mass index (BMI) at the start of the study was 25.1 (slightly overweight). None of the participants were obese (BMI of 30 or higher). Women who lost as little as 2 kilograms (4.4 pounds) and kept it off had a lower risk of being diagnosed with breast cancer during the study period than those whose weight remained relatively stable. Losing nine or more kilograms (20 pounds) and gaining some (but not all) of it back was also associated with a lower risk of breast cancer.
Sustained weight loss has also been associated with improved cardiovascular health. (See Regaining Lost Weight Negates Many Cardiometabolic Gains, January 2020.) The authors of this study hope their findings will motivate overweight women to lose some weight and keep it off with permanent behavior changes.