"The evidence favoring a new approach came first from comparisons of
various populations around the world. People whose diets were based
mainly on plant-derived foods -- that is, rice, noodles, beans, and
vegetables -- were less likely to develop diabetes, compared with
people whose diets are fattier or centered on meatier dishes. For
example, among people following traditional Japanese diets, diabetes
was rare. Studies show that when people moved from Japan to the U.S.
and adopted a Western diet, they were much more likely to develop
diabetes."

But india is the case study that contridicts this, it has the highest
rate of diabetes. None of the places referenced did not eat meat. But
what is more important is the amount of food eaten and the level of
exercise. When the japenese came to america calories went up and
exercise down, weight increased. That has now become the patteren the
world over where diabetes is high regardless of meat consumption;
remembering india again at the top of the list.