Steven, thanks for your correspondence. I shouldn't say "eschew" because I don't entirely abstain from meat and dairy. I keep chickens and eat their eggs. I eat the occasional cheese on pizza. And (though it's been a while), I eat some meat from a local farm.

From all of my research, the claim that plants have been a large part of the human diet for a mere 1% of our historical existence is not true at all. It's quite the opposite. The National Geographic article "The Evolution of Diet" is one of many that covers the evidence well (link below). And the evidence is clearly that, while varied by region and other factors, foraging was for millennia the backbone of diet, meat being a pleasant surprise when it was possible.

Today, there are copious alternatives to meat to get the same nutrients. It takes some planning and effort to abide by a plant-based diet, but it also takes planning and effort to eat the right kinds of meat and avoid what's processed or causing animals and ecosystems undue suffering and harm. So, a diet that's rich in a variety of plants and grains and occasionally sustainably-sourced fish and meat and dairy seems to be optimal for many, if not most people.

Of course, it also seems to depend on your recent ancestors, and where they lived and what they ate, influencing your genetic predispositions. (Lactose, starches, beans, etc.) It's a complex issue.

TJ

https://www.nationalgeographic.com/foodfeatures/evolution-of-diet/