I've always thought that the BMI scale is tilted towards heavier women, probably because men can look best at a BMI around 23-24 (lots of natural muscle, low bodyfat), while women usually look best at the lower end of the healthy range. Or maybe it's just that women are more prone to understate their weight, so that skews the perception. But to say a BMI less than 22 is slim, LOL. 22 is pudgy (edit: it is on my body, apparently it isn't for other people).