That’s why the county level data makes the trend that much more obvious, because the states tend to clump big groups together. Here’s an example.
There, you can see that Colorado is special in that its rural counties tend to be low obesity, compared to even its neighbors in the Rockies. You also see a sliver of green following the Appalachian Mountains.
And obviously it isn’t the only factor. Poverty is really important, as are lifestyles (and the intentional and unintentional features of any given community in incentivizing or disincentivizing things like walking, regular exercise, eating healthy, etc.).
One of the practices that the FTC sued Amazon over was their requirement that sellers list their lowest prices on Amazon and outsource fulfillment (and give up a huge cut) to Amazon in order to qualify for Prime and good search results.
The result is that even though most sellers can afford to sell on their own store and keep a larger percentage of the sales revenue, they’re not allowed to actually undercut Amazon’s prices. And so Amazon has shielded itself from price competition, despite engaging in pretty expensive practices (free 2 day shipping for most items and places, free 1-day or even same day shipping for some items in some places). And they did it with contracts instead of actually competing.