Your comment just reminded me of an incident during my long-gone high schools days when another student asked our biology teacher about people becoming vegetarians. The teacher laughed and then said basically that it was silly -I'm using a mild word here. He said we humans belonged to the animal kingdom and were meat eaters and to anyone saying something different to simply point to our own canine teeth that were made to tear like many other meat eating animals in the world.
This teacher was certainly of the 'old school' type. As times and perceptions change they get fewer in numbers, fortunately.
His logic isn't really convincing either, even then. In the animal kingdom we have all of it: omnivores, carnivores and herbivores. We humans are omnivores, that much is true. However, we are also conscious beings and thus can make conscious choices (be they related to health or ethics or spirituality, or all of it).
So we have the whole range to choose from and make a conscious choice - unlike animals who are driven by instinct and 'program', I suppose.
Also, this type of teacher maybe did not see the inconsistency of this 'logic'. For example, 'real' canine teeth are for hunting animals in the wild and eating them raw on the spot. That is hardly possible for us, compared to the real predators we have stubs. And we have to prepare our prey after killing it by cooking or at least exploiting and preparing it in some other way. We do not just hunt them and tear them apart like animals out in the wild.
He might argue from the 'evolutionary' standpoint - and I'm sure in his speech he mentioned this word quite a lot because this type loves the term 'evolution' making everything sound so justified and 'sciency'.
However, are we humans really on a natural(ly evolved) diet nowadays anyway? With all the toxic unnatural chemicals and substances we add to our food. With GMOs? With all the mass production of animal slaughter and pre-processed 'fast' food without any nutritional values?
Or how about our excessive sugar consumption of nowadays, which is highly unhealthy and unnatural? Or how about milk and dairy products? Is it 'natural' for a mammal to drink the mother's milk of another (!) mammal after the age of one or two? No other beast of the mammal animal kingdom does that. It is not surprising that we get health problems due to dairy and milk.
But maybe all of this is then called 'evolution' too.