Science News focuses on a study that said urban sprawl can be partly to blame for the average increase in obesity America's seen over the past few decades.

The question, it seems, is selection vs causation:

He and other researchers have evidence that associates health problems with urban sprawl, a loose term for humanmade landscapes characterized by a low density of buildings, dependence on automobiles, and a separation of residential and commercial areas. Frank proposes that sprawl discourages physical activity, but some researchers suggest that people who don't care to exercise choose suburban life. Besides working to settle that disagreement, researchers are looking at facets of urban design that may shortchange health.

My personal theory? "A bit of both."

Yes, people who aren't really interested in exercise might choose places that don't offer them the option to exercise. However, as far as I am aware, most people prefer their neighborhood to have those amenities anyways - it raises property values, for example.

Living in Houston, sprawl is a major problem. The commute I do to and from work every day would have people wondering how it is I manage, back in my hometown of Milwaukee. (With no traffic, it clocks at 20 minutes; with traffic or accidents, up to an hour 30 on a really bad day). There are people who live further out, and some of my co-workers have a minimum 1-hour drive presuming no traffic just to get to work.

In addition, yes, there are other problems caused. The complaint in the article about lack of restaurants in walking distance is a bit silly; if you can't walk, cook your own meal or you'll have to drive. If you're too lazy to cook your own meal or don't know how, you've got bigger problems.

However, a long commute can be draining. Even when you're just sitting in the car, sitting in the car in stop-and-go traffic is draining. You get out of the car feeling tired. Further, a commute that's 45 minutes (as opposed to 10-15) is less time that could theoretically be devoted to exercise, and more importantly, it's 30 minutes of daylight (the time when most people are most active and most likely to exercise) lost. Getting home in the winter months, when it starts getting dark, exercise seems less a priority mentally because it's "already nighttime."

Is the study foolproof? No. Can I see where reason comes in that sprawl might be "a" factor in contributing to obesity? Heck yes.