There is a reason the Dalai Lama (nor any Tibetan) is not a vegetarian...not much arable land above 3k meters (well, you can grow some barley). Likewise, next door India has so much arable land vegetarianism makes sense, China on the other hand is in between, being fairly mountainous and lacking much arable land (so they have more vegetables but still rely on meat).

Worldwide distribution changes things up a bit, but barring that entire cultures fit their habits according to the land they had, not vice versa.