I think people were already eating animals, but the animals had no fear of mankind before the flood. I think God said "they'll always be wicked, and they're going to eat my animals, so I better put some fear into them so the animals have a chance." (just kidding mostly! LOL)
and i agree. I believe we were created to be vegan. But God also put adaptability into every form of life, so that human beings can live in any environment, even in places where vegs don't grow, such as the arctic.
It's important that we don't get judgmental towards people who choose to eat animal flesh, because God gave permission for it, and even told Peter that all of it could be food, not to call something unclean that God had declared to be clean (He had a vision, in the book of Acts...don't remember what chapter)
IMO, we've gotten completely out of hand, and I REALLY think the way animals are produced for food in our culture is morally repugnant and I believe God does not smile upon it AT ALL. But...to me it is sin. I mustn't judge others, because to them it isn't sin.
I like being healthy, though!