Are you loving handicapped?
I'm going to assume judging by your name that you're a halo fanboy and therefore you desperately want zombies to be real so you can be mashtr chef and save the world and stuff, but just for a minute try to listen to logic.
Zombies are basically humans without the intelligence that makes humans the top of the food chain, one could compare zombies to the extremely mentally/physically handicapped, now you try to tell me about the last time you saw the kid who can barely wipe his own ass take over the world.
Also you didn't even address the bigger point of the "zombies have too many natural predators" argument, flies, maggots, small reptiles and mammals all put zombies in extreme danger, if you've ever seen something decompose it's a really interesting thing, all the soft tissue goes first, that would mean zombies would be skeletons in days.
And finally the invasion would never happen because of two things:
The CDC
Biting doesn't spread infection very well