“Adequate weight was defined as a B.M.I. of at least 18.5 and no more than 27.5. The cutoff for “overweight” is 25, meaning that you don’t have to be thin; you just have to be less than obese (B.M.I. 30). Finally, exercise was defined as 150 minutes a week of moderate-intensity activity or 75 minutes of vigorous-intensity activity. That’s a reasonable and quite achievable goal.”