I think what you're missing is that it's all fictional and, like vampires, the "rules" vary from writer to writer
Original Mexican Zombies (or is it caribbean zombies) would suddenly realise they were dead and return to their graves if they ate meat.
( MONO!, Tue 27 Sep 2011, 13:23, archived)

Wait, people are allowed to make up their own rules when writing fiction?

( BraynDedd Natasha Kaplinsky's labia majora, Tue 27 Sep 2011, 13:24, archived)

Apparently.

( MONO!, Tue 27 Sep 2011, 13:26, archived)

The CUNTS.

( Blue Star was working part time at the 5 and Dime, Tue 27 Sep 2011, 13:28, archived)

I thought it was salt?

( Wicca'd Witch needs ideas for a new sig on..., Tue 27 Sep 2011, 13:26, archived)

I read meat somewhere, though you might be right
But it was all superstious stuff anyway so it probably varied greatly depending on who you asked.
( MONO!, Tue 27 Sep 2011, 13:28, archived)

It's tofu
Zombies are inherently intolerant to soya products.
( Lord Gnome, Tue 27 Sep 2011, 14:08, archived)