There’s this new fad going around called the “palaeolithic diet” (or at least, that’s what it should be called. I’ll have none of this American “paleolithic” thank you very much). It is essentially people trying to eat what our ancestors ate, the logic beign that it is what we’ve evolved to deal with and will thus offer some health benefits.
This logic, however, misses out on the best part of being a member of the genus Homo: our generalised anatomy. Our longest lived ancestor was Homo erectus and it was able to live as north as Georgia (the country, not the state) prior to fire and even made it to the chilly climes of Britain without clothes.
Imagine living in such a miserable environment with nothing more than a few handaxes and maybe fire (the evidence is somewhat circumstantial for it occurring that early).
We’re well adapted to being generalists, able to survive in a variety of environments. This includes our digestive system. Over the course of the actual palaeolithic we’ve lived and eaten in dozens of environments because we’re generalised and that’s what we do.
There is no magical mixture of berries and meat that we’ve specalised to be extra adept at consuming. Positing that as what we’ve evolved to do is the very antithesis to our actual evolutionary history. Generations of hominins died so you wouldn’t have to live off berries and meat.
Now, that’s not to say living of whatever mixture of meat and berries they say is good for you won’t actually be good for you. It may very well be. But if it is, it’s because it’s fulfilling your nutriotionary needs, not because your body has evolved to be super-great at digesting it.
So when you plan your diet, base it around your dietary requirements and not some invented evolutionary reasoning instead.