Bear with me here a moment, as what I'm about to type could easily be misinterpreted as racist or classist, but it's not.

I think the overwhelming factor in obesity is economic, not religious. Our poor, statistically speaking, are most at risk for obsesity. The fact is, the states ranking near the top are also some of our poorest states, and they have a higher than average minority population (which, also, have a higher propensity to be poor).

There are a lot of factors at work here...it's cheaper to eat unhealthy foods than healthy, less education, etc. But I don't think being "religious", of any particular stripe, has anything to do with it. You certainly don't have to be poor to be fat, as my spare tire will attest, but it does raise your chance. BTW, I think it also speaks volumes about our wealth as a society when our poorest are also the most likely to be fat.