Weight Loss from Activity Only Works in Thin Middle Age Women
The Harvard associated researchers assessed weight changes associated with various levels of physical activity on 34,079 women who had been followed since 1992 in the Women's Health Study. They stratified women as inactive (less than 150 minutes a week of moderate level physical activity), intermediately active or highly active if they performed a high, strenuous level of activity. All three groups showed similar weight gain over a mean 13 years of follow up.
Despite exercise, there was no correlation between activity level and weight gain except in the subgroup of women with Body Mass Index (BMI) below 25. Only in those already thin women did a high level of activity prevent weight gain.
So what are we to think about this study? First, caloric restriction is the only way to maintain or lose weight. The health benefits of exercise have been proven over and over in thousands of studies and that is not in dispute. But weight control demands caloric restriction, period.
I am sorry about these results. Truly I am.