While that is true, I think that some of these things are tied to local culture too, which is why the Coastal distinction does have some merit.

If you generally are in the Bay Area or LA you rarely see the level of obesity you see in say Houston despite the fact that both areas despite being rich have their fair share of the poor too.

Similarly for smoking. It's exceedingly rare to see public smoking in the Bay Area.

Similarly for diets. When traveling in the South I was amazed at just how ridiculously unhealthy the average food eaten by the average person there was. Everything deep fried, laden with calories, consumed along with sugary drinks.