To the Editor: The observational study by Dr Lee and colleagues1 found that relatively high levels of physical activity among overweight or obese women in the Women's Health Study were not associated with protection against long-term weight gain. On the other hand, among white women in the US Diabetes Prevention Program, those exposed to a structured lifestyle intervention (combining exercise, diet, and coping or problem-solving skills) experienced about 8 kg of weight loss during the period of their multidisciplinary, structured support.2 The report from the Women's Health Study, therefore, is consistent with less intensive obesity intervention trials that found little or no weight loss following exercise or dietary treatments.
Kahn HS. Physical Activity and Preventing Weight Gain in Women. JAMA. 2010;303(24):2475-2476. doi:10.1001/jama.2010.824