Paleo maximalists currently on suicide watch as their foundations are being shaken. Flatbread may have crossed the lips of prehistoric man and not just meat and berries.
Only one settlement so far was found to have flat bread. So Paleo people's beliefs aren't that shaken.
Oh, I wouldn't take it that far. You can always take it back to primate diets, and evolve forward until humans emerge, and there you'll find an era for which the concept still rings true.