Not enough people paying attention to your pet issue? Just compare it to terrorism. That's what our nation's surgeon general did recently. Dr. Richard Carmona warned that unless we do something about obesity "the magnitude of the dilemma will dwarf 9/11 or any other terrorist attempt."
If obesity really is that threatening then maybe we should step up the fight against suburban sprawl. After all, politicians and activists are always telling us that suburbia makes us fat and at first glance it seems like they might be right. Suburbanites drive everywhere — to work, the grocery store, even the mailbox. If you drive everywhere, it's easy to see how you could become flabbier. And yet a new study challenges our intuition.
Researchers from the University of Illinois studied ten counties in the Chicago metropolitan area and found the slender people were not concentrated in the densely-packed center city, where it's relatively easy to get around by foot or by transit. Rather the fit folks were most likely to live in suburban neighborhoods, 10 to 20 miles outside the city.
And this study isn't some oddball loner in the academic research. It squares with previous research conducted at the University of Michigan and elsewhere. Yet we shouldn't jump to the other side and assume that suburbia makes us slender. Even the University of Illinois study develops its conclusions from a popular but imperfect gauge of obesity, the Body Mass Index. Indeed, the link between suburbia and fatness is so tenuous that about all we do know is that we don't know much. Recently the Institute of Medicine and the Transportation Research Board reviewed the literature and found that evidence that suggests suburban sprawl makes us slothful is "currently sparse."
Yet when discussion turns to the relationship between suburbia and health, we are so quick to assume that suburbia is bad for us. Why? One reason is the nature of news. A study that finds no link between suburbia and something horrible probably isn't going to interest many local news directors. They're more likely to run another segment on the cockroaches their hidden cameras spotted at local restaurants. But produce a study that reveals something dangerous and the news director's eyes widen. A 2004 study suggested suburbanites die sooner than other people and it quickly made its way through local media outlets, as well as big-time national venues like CNN and Newsweek.
Intuition is another reason we're quick to assume suburbia is harmful to our health. We all know plenty of suburban couch potatoes and we recognize that suburban living can make it easy to avoid exercise. Yes tract home dwellers often substitute driving for walking, but it's more than that. All sorts of new gadgets and products make it easier for us to do less. Today's teenagers forget that people used to have to get up off the couch to change the TV channel. We no longer have to push our lawnmowers, we just ride them. Bags of pre-chopped salad spare us from chopping lettuce ourselves and battery operated toothbrushes let us avoid burning another handful of calories.
It also seems intuitively obvious that city living would help offset the sloth-enabling aspects of modern life. And since they often run errands by walking, urbanites often do find it easier to incorporate activity into their everyday lives. But such an arrangement isn't necessarily healthier.
Imagine you live in the epicenter of American urbanism, New York. After a long day at work, you hop on the subway and travel to the station closest to your apartment. You walk from the subway station to the grocery store, buy some groceries and head home. From a health perspective, some exercise is better than none, but intensity matters too. At the end of your long day, you might be too tired to go to the health club for the type of target-heart-rate-achieving exercise that doctors say is so important. And even if you still have the energy, you might not have the time.
Contrary to conventional wisdom, commutes tend to be longer in higher density areas and how you travel also figures into how long you travel. Traveling the suburban way (by car) is usually much faster than traveling by public transit, which is more common in big cities. According to the Census Bureau, transit commuting — even in New York — typically takes twice as long as car commuting. Over the course of a month that's an extra 16 hours that could be spent on treadmills, swimming laps or playing tennis. And so while suburban living can make it easier for us to get flabby, it can also provide us with more time to get fit.
We should continue to investigate how our physical environment impacts health, but we shouldn't let this debate distract us from the big picture. Even if obesity were as threatening as terrorism that still wouldn't give us reason to attack suburbia. Neighborhood design might make it a little easier or a little harder to stay in shape, but other factors, from education to income, are much more closely tied to good health. And ultimately, the key to healthy living is self-discipline, and that's something that can be practiced anywhere.
Ted Balaker is the Jacobs Fellow at Reason Foundation and co-author of an upcoming book about mobility and congestion (Fall 2006, Rowman & Littlefield). This column originally appeared at TechCentralStation. An archive of Balaker's work is here and Reason's growth and land use research is here.