One thing I never see is that Zombies would eventually have to run out of energy if they don't get any food. The rate of zombie demise from starvation would need to figure into it. Eventually they will die from lack of food, water and electrolytes, the latter would immobilize their muscles. Zombies aren't known for having a balanced diet. Eating just meat wouldn't provide them the energy needed to keep going. Lying inert still uses energy.
So for the sake of research based on "science", if we were to consider vampires in this model, would you consider Tom Cruise's survival characteristics in Interview with a Vampire an outlier?
If a vegan becomes a zombie, are they classified as a zombie if they continue to not desire meat? Are they technically a vegetable and not a zombie? If so, how do you feel self defense laws would apply in that scenario, since it is likely assumed that shotgun-to-the-face is perfectly legal for their meat-craving brethren...
Shit, I better stop now before this goes straight to plaid.