I've only been following the zombie phenomena for a couple years, and don't know all the lore, so I have some confusion about their physiology.
1. Given that they are dead re-animated beings, whose flesh is necrotic and all internal functions have all ceased, other than the nervous system which can still crudely get the muscles to work facilitating locomotion....how or why are they motivated to feed? Eating may put food in the stomach, but the nonfunctioning circulatory system is not taking nutrients to the brain or muscles. It seems a pointless exercise, other than for the sake of terror. What is their motivation for food?
2.) My impression is that zombies eat the living, and only the living. They don't eat each other, they don't go to the supermarket meat counter - they desire the flesh of the living. But once they start chomping, the living quickly becomes the deceased. How long are we palatable to the zombie? Do we cease being yummy once we quit wiggling and screaming?
...and STAY out of the WOOLWORTH's!!!!!!!!!