I'd be surprised if any significant part of your diet resembles what we evolved to. Our food has been bred for taste and sweetness, and lately also to optimize storage, transport and mostly profit. Instead of seasonal variations we get the same food all year around. Instead of regional food, we consume food grown all over the globe. We consume too much and move too little. But the real scare is we eat too much veggies?

Millions of people, entire cultures even, live on a vegetarian or vegan diet. Including high performing athletes. It's certainly possible.

On the other hand, millions of people live on an omnivore diet so bad it makes them sick.

I'm not saying one is good, the other is bad. It's obviously possible to live a healthy life either way (which was my initial intent in brevity), and it is possible to live an unhealthy life either way. Living meat-free in itself is as healthy or unhealthy as living meat-eating. It depends on how you do it.