These "caveman" diet fads are really weird. Lets say hunter-gatherers instead, that describes our collective deep past much better. Their respective diets are s

These "caveman" diet fads are really weird. Lets say hunter-gatherers instead, that describes our collective deep past much better. Their respective diets are super varied and diverse, from almost exclusively meat in arctic climates to a wild mix of hundreds of species from different biomes in the Kalahari to basically pescatarian in some very maritime places. Then there's lifestyle – nutritional needs will vary greatly according to whether one routinely walks 20km a day, lives in the cold, or stares at a screen in airconditioned offices, and it's not just about calories, sometimes it's probably even a genetic thing – there seem to have been adaptations to an almost exclusively carnivorous diet. Replicating their diet wouldn't be great for most people. And on top of all that there's the ten-ish millennia of adaptation to agriculture and raising livestock that you mentioned. I don't think there is much to it save for some very general insights into how diets and the environment interact.