What you eat depends on what you can get from the land you live in. You can't grow much above 4,000 meters or near the arctic, obviously. Indians are mostly vegetarian because you can grow alot in India, the much of the rest of the world isn't so lucky (I always crave veggies whenever I tour in high country because they are so unavailable).
yes... and so different groups of people were under different pressures. So when oneeyedpigeon said "Eat food. Not too much. Mostly plants.", and you responded mentioning the Inuits, I decided to remind you that that's not relevant. You haven't made a counterargument to the claim that you should be eating mostly plants. A given person's ancestors were probably not under the same sort of pressure to consume meats.
"mostly"? I would love to know where this statistic was pulled from? Personal experience living in India for 5 years suggests that only Brahmin Hindus and a few other castes are purely vegetarian. Every one else eats meat albeit not as frequently as Americans. Wikipedia stats suggests 20-40% (a huge variance).
The semantics police are out in full force today :) BTW, The Microsoft cafeteria in Bangalore is pure veg.
When I was working in Delhi, the office canteen offer only veg food 4 days a week, with an optional meat item for a small surcharge on Fridays only. Down south, 100% veg food in restaurants is pretty much the rule, not the exception, although it's not hard to find fish/meat if you look.
Also, a good Indian friend of mine is nearly 100% vegetarian, except that every now and then he gets a craving for a cheeseburger. That's "mostly vegetarian" in my book.
...and getting back to the health thing, it's kind of striking how many obese Indians are Brahmins, who may keep veg but like to slather everything in ghee (clarified butter).
Vegetarianism != Healthy. A diet high in protein/fat doesn't necessarily have a causal link with weight increase. The problem is eating beyond what your BMR/TDEE is. A large portion of Indian food is calorifically rich, e.g. bowls of rice and flat breads.