Adding to your original post, more people get diabetes in the US than foreign born. CDC data is insane with risk factor ratios:
http://www.cdc.gov/diabetes/news/docs/lifetime.htm


But those ratios explain nothing about causality, only risk factors are mentioned mainstream.

I've witnessed this first hand, so it is interesting to point out that it could be numerous factors causing diseases to be rampant. With empty foods, no nutritious value, it exacerbates the problem with chemical addiction like too much sugary foods devoid of life. US born start off eating foods that have little value and are biotic-free.