4. Then there's the practical side. Think about your own performance after a big meal. Studies have shown that a dog (or human, I believe) with food in its gut runs slower, is less agile, and has less stamina than one with an empty stomach. Precious energy (and blood supply) can support muscles and respiration, not digestion. Fluids required for digestion are then available to hydrate those muscles. And most importantly, the soggy, heavy wad of food isn't bouncing around inside his body, zigging when he zags and possibly causing "gastro volvulus" or stomach twist–a frequently fatal condition.