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.).