The May/June 2010 issue of the American Psychologist has an article on the problem of immigrant acculturation. One section focuses on the "immigration paradox." This refers to the fact that the more an immigrant is assimilated, the greater the risk of bad health outcomes. This is the case for psychiatric disorders, drug and alcohol abuse, bad eating habits, obesity, diabetes--just about anything you want to examine. It's such a big problem, it gets it's own name (that's Immigrant Paradox, in case you missed it).
But for some reason, among the list of policy recommendations, I can't see the obvious suggestion that we discourage folks from moving to unhealthy America, and that we encourage them to return home if they're already here.