[bitstein]

> people have lived in all parts of the world, with vastly varying diets

Yes, though all of them ate animal products and highly valued various animal fats.

That being said, we can find evidence of people eating all-meat diets in every corner of the globe, and often times if there were more agricultural people nearby, the carnivores were healthier and stronger (such as the Masai vs. the Kikuyu, the Sami vs. southern agricultural Swedes, etc.). Just because people were healthy eating one type of food does not mean they could have been even healthier eating another food if they had access to it.