A Tale of a Few Cities: How Sprawl Affects Your Waistline
A few decades ago, suburbia didn't seem too far from utopia. Postwar families flocked to these new neighborhoods with their affordable houses, green lawns, and easy access to the city.
There wasn't much outcry about the lack of bike lanes or walking paths or stores within walking distance. Adults could drive wherever they wanted to go. In this new way of life, cars ruled.
A sprawling society
The suburbs still have their appeal, but there's a downside to all that comfort and convenience. A study published in the American Journal of Health Promotion found that people living in sprawling suburbs were slightly less active and weighed more than people living in densely packed communities. To put it another way: There is now scientific evidence of an association between sprawl in a neighborhood and sprawl in the adult waistline.
Researchers made the connection between suburbia and obesity after comparing 448 counties and 83 cities across the United States. Each area received a "sprawl index," a score largely based on population density. Geauga County -- a suburban enclave outside Cleveland -- took the honors as the most sprawling in the study. Not surprisingly, places like San Francisco County, Philadelphia County, and four boroughs of New York City landed at the opposite end of the spectrum.
After measuring the sprawl of each county, researchers took a hard look at the inhabitants. Surveys conducted provided detailed information on the health, lifestyle, and body weights of adult residents. After controlling for race, education levels, availability of leisure time for exercise, consumption of fruit and vegetables, and other factors that can affect body weight, researchers found that people in New York County -- the most "compact" county in the study -- walked 80 minutes more each month and weighed an average of six pounds less than those in sprawling Geauga County.
Six pounds may not seem like a big deal. A good eater could easily gain that much between Christmas and New Year's Day, and a dedicated dieter could lose that much in just a few weeks. But in a country already struggling with an epidemic of obesity, those six extra pounds could be a significant threat, says Tom Schmid, PhD, a researcher with the Centers for Disease Control and Prevention (CDC) and co-author of the study.
"Imagine two hypothetical communities of 100,000 people," he says. "One community as a whole would weigh 600,000 pounds more than the other." Those 300 tons wouldn't be distributed evenly. Some people would remain average, while others bulged with extra weight. But in the big picture, the whole town is at higher risk of obesity-related diseases. According to Schmid, the extra pounds can raise a community's rates of heart disease and type 2 diabetes. It's a big price to pay for a quiet neighborhood and a big lawn.
Arlin Wasserman, an urban planning expert intrigued by the connection between weight gain and the suburbs, didn't stop at an extra six pounds when he moved from Philadelphia to the suburb of Ann Arbor, Michigan. Wasserman, then a member of the Michigan Land Use Institute, says he promptly gained 15 pounds in a town where he could no longer ride his bike everywhere. Another move, to the sprawling town of Traverse City, Michigan, helped him pack on another 20.
Four years ago, Wasserman made a break from sprawl and moved to St. Paul, Minnesota. He lives just a block and a half from an 18-mile-long bicycle path -- a great place to walk with his border collie -- and he walks to about half of his meetings. He says his weight has held steady ever since he made the move. "I give two-thirds of the credit to where I live," he says. "And one-third goes to the border collie."
Inactive by design
Urban planners and health experts have long known that suburbia wasn't exactly a hotbed of active living, at least for adults. In fact, the suburbs seem expressly designed to keep people as still as possible, says Marya Morris, head of the Planning and Designing the Physically Active Community project at the American Planning Association, a nonproft group of city and urban planners as well as elected officials.
In some places, neighborhoods stretch seamlessly for miles with no parks, stores, offices, or even schools to break the monotony. If people did want to ride their bikes or go for a walk, they'd be hard pressed to find a destination within striking distance. In contrast, people in cities such as Brooklyn, San Francisco, or Philadelphia routinely walk several blocks every day to their jobs, the subway station, or the corner grocery store, she says. It's not exactly a trip to the gym, but it is real exercise.
Even if you think about strolling over to your friend's house in a neighboring subdivision, the suburbs often put up roadblocks to walking or biking, Morris says. Sometimes stores or neighborhoods are on the other side of a four-lane highway, and the main streets are generally designed to accommodate the maximum amount of traffic moving at the greatest possible speeds -- not exactly the ideal scenario for either a pedestrian or a road bike. Though some cities have made bike-friendly changes -- Davis, California, for example, has built a thriving bike tunnel under a highway and railroad to connect both sides of town -- many suburbs are still stuck in an outmoded design that makes it hard to walk anywhere.
Things are easier on the side streets, but it's still hard to get around. For one thing, the side streets often don't connect, Morris says. A walk that should only take 15 minutes could easily take 30 minutes, more if a person happens to get lost in a maze of cul-de-sacs and dead ends. If the neighborhood doesn't happen to have sidewalks -- and many don't -- that walk becomes even less inviting.
Smarter growth, healthier people?
Over the last 15 years or so, many urban planners have sought a better design. Instead of signing off on yet another expanse of houses, they encourage the development of denser communities with a mixture of houses, businesses, and parks. This movement -- often called "smart growth" -- was originally intended to promote vibrant communities, minimize traffic congestion, and protect farmland and other open spaces while creating new homes. The possibility that smart growth could also help keep people more slender and active is definitely an added selling point, Morris says.
"Planning is very politicized," she says. "The fact that we have people with MDs backing us up makes a huge difference." Morris and others who want to promote active, livable communities still run into plenty of skepticism, but now they have research in their corner. "A lot of people kind of roll their eyes when I talk about this. They say, 'Are you telling me that wide streets make people fat?' They're more likely to believe it now."
Indeed, many experts now believe that urban planning may play an important role in the country's battle against obesity. Government agencies such as the CDC and charitable organizations such as The Robert Wood Johnson Foundation are putting their expertise and money into this new arena. The foundation alone has committed more than $70 million to promoting smart growth and active communities. Among other things, communities are using grants from the foundation to build trails, parks, and bike paths.
Of course, researchers have to contend with what some have called "The Urban-Suburban Paradox." According to a study recently published in Environmental Health, at least one sub-section of urban dwellers are less likely to be physically active and more likely to be obese Compared to suburban residents, inner city populations have higher rates of obesity and inactivity despite living in neighborhoods that are dense, have excellent street connectivity and (where) streets are almost universally lined with sidewalks." Noting that most research on obesity focuses on the suburbs, they conclude that we need more research on combating obesity in urban areas.
Meanwhile, at a time in which many cities and towns have made small changes to increase physical activity, at least one new town is taking "smart growth" to extremes. Stapleton, Colorado, a community growing on the plains east of Denver, fits the dictionary definition of a suburb, but it certainly doesn't fit the mold. Stapleton will have a network of parks and trails that connect people to grocery stores, restaurants, and other destinations. Planners expect to attract 30,000 residents over the next several years. This small town is a major experiment. If community design really does matter, the residents of Stapleton should turn out to be healthier than typical suburbanites.
Of course, not everyone is built for Colorado winters, and not everyone can afford a place in Manhattan or San Francisco. In short, many of us are stuck in active-living wastelands. If you live in a neighborhood without bike paths or sidewalks, it may take a little extra effort to put exercise into your life.
Walk when you can. Join a gym. Find a nice park where you can jog or play Frisbee with the kids. (You may have to drive to get there, but it will be worth it.) And when it's time to pack up and move, remember that there's more to a house than the square footage and the color of paint in the bedrooms. More than ever, the neighborhood matters.
Interview with Arlin Wasserman, an urban planning expert
Interview with Tom Schmid, PhD, a researcher with the Centers for Disease Control and Prevention
Ewing, R. et al. Relationship between urban sprawl and physical activity, obesity, and morbidity. American Journal of Health Promotion. September/October 2003. 18(1): 47-57.
Lopez, Russell et al. Obesity, physical activity, and the urban environment: Public health research needs. Environmental Health: Sept. 18, 2006; 5:25. Interview with Marya Morris, head of the Planning and Designing the Physically Active Community project at the American Planning Association.
Fiske, Brian. Urban Treasures. Bicycling Magazine. http://www.bicycling.com/article/1,6610,s1-2-16-14593-10,00.html
Smart Growth Strategy/Regional Livability Footprint Project. What is smart growth? http://www.abag.ca.gov/planning/smartgrowth/whatisSG.html