What they don't point out is that the opposite works too, with people that have less muscle, probably caused by a sedentary lifestyle, being indicated as healthy when they're overweight for how much muscle they have. I know several very inactive people that are legitimately in the healthy BMI range, but if one were to do an actual bodyfat measurement they'd find out they are fatter than they should be.   That was probably me until fairly recently. I've never been over BMI 25, but I've never had any significant muscle mass, either. Thanks to FPH, I'm actually starting to properly get in shape for the first time in years. Not being fat is nothing to brag about. All you have to do is just not stuff your face. It's the baseline, the bare minimum. But now that I'm working out regularly, I feel like I'm actually accomplishing something.