I don't reward myself with food I like naps. I'm actually lazy. I used to joke I sleep as much as an Abra.  If I have to go out for the night, I take a nap before I go out. I'll take a nap on Sunday after coffee.  I'll run 3.5 miles then come home, shower, and nap.  Now if I was fat instead of just lazy, replace nap with food.... And Abra with Snorlax.  You get energy from food; Sugars especially. But I'd much rather catch an hour of warm sleepy goodness than stuff my face. And that's why I think I have a BMI of 20.9, but really it's probably self-control.  Anyway, my point is, don't blame laziness. Sloths are pretty slim. It's the self-control thing that does it.  We should think about making Sloths the icon of skinny people. Their metabolism is pretty slow, they don't overeat, and they rock the pull up bar.