"What nonsense. God told Noah and his descendants to go eat animals just like the plants"
Um, that was after the Fall. Check out what God said to Adam and Eve before the Fall. I think that was Kosta's point. We Orthodox remember this during all of our fasting days and seasons, in which we eat nothing that comes from an animal. (But does that lamb ever taste good on Pascha after being without meat for nearly two months!)
And my point was that God continued to evolves man's thought process. God commanded man to eat plants and animals. It wasn't just that Noah was hungry and started eying the chicken coming out of the ark. God told Noah to get the knives out. This is no different than God telling Peter not to consider things unholy that which God has cleansed: