You only get fat if you don't excercise. Regardless of the moral background of selling a "very effing large pizza for only $10," if you get off your ass and don't eat too much food without excercise, you won't gain weight.
Michael: Jodie, how's my schedule look for today? Jodie: You've got a conference and dinner party at the Japanese Embassy regarding wildlife protection. Michael: Oh, yeah...sorry, but I'll have to cancel that. I'm heading out to save America!