I still think it's a good metaphor: they eat constantly while still eating regular meals that must be huge. Like probably a lunch and a pizza or two burgers plus lost of soda or alcohol per day. I'd say 3000 kcal easily per day assuming they do at least _something_ (and that's not much) to add to their basal metabolic rate. They are completely in a feeding mode that is required just to upkeep the amount of fat tissue in their bodies. If that doesn't remind you of a barnyard animal, I don't know what does.