That's the conclusion of a new archeological study. And that's so far back that the article I saw referred to those meat eating fellows as "proto humans", based on the current understanding that our particular species has only been around for about 200,000 years (although I'd wager we're an older species than that).
Well, you vegan freak, you aren't eating a natural diet. Evolution abhors you. Your DNA is screaming at you. Nature didn't make you to have a diet of a bacteria.
Of course, it didn't anticipate you sitting around in a cubicle all day either.