The problem with eating only vegetables is that you actually turn green. Meat gives you the red color under your skin. The lack of red some how brings out your veins. Veins carry blue blood and shows up green when you look at your skin. For those of you who went to NYC public school, arteries carry red blood.
So what else happens when you only eat vegetables? You lose bone. In order to eat enough to feed your body, you would have to graze on grass all day long non stop - like a cow.
I don't eat a lot of red meat, but I do eat a lot of sea food.