I have one of those at work... He regularly goes on "diets" and he's only allowed to snack on (buttery, buttery) popcorn.  I never quite understood what he was expecting out of those diets until I found out that his go to snacks are Reese's cups...  Not one or two either, he keeps bags around to snack on during the day. But anyway, what I'm saying is, his weight is CLEARLY a genetic condition.... Totally.