Hmmm . . . What about sharks?  They also hunt and eat meat - are they human too?

It is true, humans have been eating meat for a long time.  I suspect you find that we started eating meat because it was better than the alternative - i.e. starvation.

Your logic is deeply flawed.  It seems to be: (1) we did something in the past, (2) therefore it must be natural for us to do it and (3) therefore, we should keep doing it.  Would this logic apply more generally?  How about to war?  Or racial prejudice?  Or how about religious persecution?

The question today is not so much what kind of diet is natural for us, but what kind of diet is going to most strongly contribute to human flourishing.  I think one has to acknowledge that there is a growing mountain of evidence that says, at least in terms of diet, the best path forward is a whole foods, plant-based diet.