I mean, eating meat is natural. Animals eat other animals, and animals are innocent to anything and don't commit sins (at least, IMO they don't). So then for use eating meat would be ok too. As long as you kill them purely for food and not just kill for fun I think it's fine.
In many religions animals are good offerings, so then it's a good thing..
Though possibly you could also count the rule of "thou shall not kill" also for animals, and not only humans.
But then people of no religion, why would they?