"Maybe I should set aside $10 every week, which I get back at the end of the week if I don’t eat anything bad for me."

A Freakonomics diet idea. I like that idea, even at the low $10 level. It's not really enough to be paid for the amount of trouble, and since you're paying yourself, it's nothing. But little things like that can jostle you into behaving differently.

There's a big obesity forum at the link, with several authors. The $10 idea is from Havard econprof David Cutler.