Thats because they arent following the right vegetarian diet. Vegetarians arent necessarily healthy.Many of these people tend to consume a ton of pasta, cheese, soya, frozen and fried food which is not a healthy diet.
In some societies it should be harder to be a vegetarian than in others too.
Vegetarians can be just as healthy as everyone if not more than meat eaters if they have the right diet. Vegans are a different story though. If these can be healthy it sure is very hard
I know plenty of vegetarians including indians and they are healthy. Not overweight or skinny either
Are the indians you met permanent residents in US or working for years in US btw?