Because it's easier to pawn the accountability to some mysterious 'disease' than it is to say I should eat less...I have a buddy who is a extremely fit, but when we hang out on the weekends he eats like shit, wings, pizza, etc...but the thing is I am not there with him the other 6 days out of the week when he wakes up at 5am to go for runs...these hams see one meal or one event where a person gorges on pizza and automatically assume their entire life is riddled with eating so it's not that they are disciplined, its that I have condishuns which prevent me from being thin