If you look at the eyes of Indians that are strict vegetarians their eyes look too deep in their skull and the tissue around them always seem bruised and puffy. The children of Indians raised in the United States seem to have different facial features probably due to a totally different diet during development.
You are what you eat.
That is an interesting observation and one I’ve noticed with the many Indian people I’ve worked with here in California. I never thought about the differences you point out between immigrants and those born and raised in the USA and what might cause them.