In the United States, there's a phenomenon of "fat cities" and "thin cities" - cities and regions where obesity is prominent, and those where it's rare. While some cities may be "fat" due to climate, culture or poverty, or "thin" because of a dense, walkable environment, it seems like some "thin cities" are self-selecting for a fit population. Denver and Boulder, for example, which attract thousands of new residents every year, drawn to the ski slopes, trails and "fourteeners" as much as a new job. Nothing is stopping an obese person from moving to Denver, or a thin person from moving to Houston, a city often cited as having a high percentage of obesity. Still, for a fit mountain-climbing, back country-skiing, triathlon-competing type, Denver is far more likely to be on their short list than Houston. If those who are sedentary, a natural environment and climate conducive to outdoors recreation aren't going to be must-haves, and they'll be less likely to seek out a place like Denver. I don't think obese people self-select to Houston because of a thriving restaurant scene and low grocery prices. It's just that the mountains probably don't matter as much to them, and the outdoorsy crowd really isn't flocking there.