I have major, major, problems with BMI as a measure. Also, I believe that the diet industry is to blame for many of the problems it claims to solve. Dieting wrecks your metabolism, and most people who lose weight on diets gain back more. So, someone can start off moderately "overweight" and end up weighing much more than they did to begin with if they just yo yo diet for a few years, which is quite common. If you google fat acceptance you can find a huge number of blogs and sites that talk about criticisms of the obesity panic.