“Subspecies” feels a bit othering. Humans have been eating meat since Homo erectus (about 2M years).
Isn't the poor health with the switch explained by the lack of food diversity? Also, wouldn't there be less meat availability after the switch from hunter-gatherer as your population grows and your crop/planting efforts grow but animal husbandry did not scale at the same pace.
Nutrition is complicated. It could be that impulsive eaters or people who make poor eating decisions rarely exclude meat from their diet, and the issue isn’t the meat so much as the rest of their diet or the sheer volume of what they eat.
In any case, there isn’t any compelling data to eat meat other than “it tastes good”. Unless you live on subsistence farming and a goat eating grass you can’t eat is an essential source of food for you.
Another thing.. Non fungicide treated plant based food seems to cause a amount of cancer. https://www.cancer.gov/about-cancer/causes-prevention/risk/s...
"Eat food. Not too much. Mostly plants." - https://en.wikipedia.org/wiki/In_Defense_of_Food
Might be simplifying things too much in general, but for the layperson it's not horrible advice - just a bit of everything, without going into excess. Some grains, veggies, fruits and berries, probably some dairy products, eggs/fish/meat occasionally too, at least for the folks for whom a vegetarian/vegan lifestyle would be be difficult.
Personally, I have both lactose free milk and plant based alternatives sometimes (there's a rice drink that I like, but oat/almond varieties are okay), some cheese (also the cottage variety) and meat sometimes, though mostly chicken instead of something like beef. In equal measure if not more, I also choose plant based alternatives too, like bean/pea/spinach burger patties, or just dishes without meat sometimes. A bit of fat, a bit of sugar, albeit limiting sugary drinks and processed foods somewhat.
Bloodwork seems fine so far, also losing a little bit of weight gradually to improve BMI, maybe should slightly lower cholesterol because it's towards the upper end of a healthy reference interval. Although I will say that sometimes there's definitely a pronounced sense of hunger, even though I've had enough food, which is annoying.
offtopic: I disagree with the "subspecies" comment from GP - it was a bit inflammatory.
I've never heard of this linkage. I've always heard it was on account of cooking the meat, rather than eating more of it.