I'm South Indian. We traditionally eat a lot of rice and lentils. Indians, Hindus in particular, consume huge amounts of diary products.
Even though we've been eating rice for centuries, I don't think Indians are well adapted to it. At least from what I've seen in my family. Most of us are overweight and/or have diabetes. Even though our family does eat meat and animal products, rice/grains are more available and cheaper in India. Meat eating takes place occasionally during the week, but mostly on special occasions and festivals.
I think non-Indian Asians might have a different carb-sensitivity, even though they eat probably the same amount of rice that we do. Maybe its because its not Basmati Rice? Very intriguing indeed.