I think you need to dole out everything for him. I know it's hard because you can't be there alll the time and he'll sneak. But don't just give him free range. Tell him, You had a sandwhich, that's enough. Too bad if he's hungry, he has to be, at this point. Know he will sneak, but it will still be less than if he's allowed carte blanche to everything. I have a 300 (more) lb difficult child. He was 200 when he lived here, he plays football and is very big all over, 200 was good, but we ruled that kitchen with an iron fist- when he left he did what he wanted, but it would have been worse. Just do your best, I know how much it hurts seeing your difficult child do this to himself, it's hard to lose weight when you're just a kid.