FEET OBSOLETE? SDSU tests view that we're plump partly because neighborhoods not 'walkable'
By Kelly Thornton
May 19, 2001
Krispy Kreme doughnuts, triple bacon cheeseburgers and stuffed-crust pizza all play their part.
But for the first time anywhere, researchers at San Diego State University are testing an offbeat theory to explain why Americans are the fattest people on the planet: suburban sprawl.
As modern suburbs have expanded, so has the nation's waistline, and researchers believe the exodus from urban centers -- where stores, restaurants, homes and schools are clustered together -- is partly to blame.
"If there's nowhere to walk in your neighborhood, why are you going to walk? We've taken the purposes out of walking," said SDSU professor James Sallis, who is leading the experiment. "The use of land now is based on what is best for cars."
His team of six SDSU students is randomly selecting 100 people in two San Diego communities -- one walker-friendly, one not -- to learn how far people walk and what environment has to do with it.
Starting a month ago and continuing through the summer, participants are wearing beeper-sized accelerometers, sophisticated devices that calculate physical activity and download the data into a computer for analysis.
"Our hypothesis is, these community designs are the root cause of low activity and increasing weight in millions of people in this country," Sallis said.
The issue is more than academic.
Physical inactivity and unhealthy eating contribute to at least 300,000 preventable deaths every year, according to the U.S. Centers for Disease Control and Prevention, and more than 61 percent of the American population is overweight -- meaning people are at least 30 percent over their ideal weight.
Even children are putting on pounds at a troubling rate: Eleven percent are grossly overweight.
At the same time, studies suggest walking trips in the United States are rapidly declining, while car trips are increasing.
In 1977, nearly 10 percent of trips were made by walking and about 84 percent were by car. By 1995, the walking figure was cut to almost 5.5 percent while car trips hit almost 90 percent, according to a CDC study. Walking or cycling trips to school made by children were down 40 percent in the same period.
"It seems like in our communities we've engineered out the opportunity to get physical activity, and it probably has to do with the way we've designed our communities over the last 50 years," said Tom Schmid, director of the CDC.
The modern suburb, where homes generally are some distance from megamalls, replaced traditional pre-World War II communities with a gridlike pattern of homes and business.
Sallis selected Clairemont and Normal Heights because they have similar populations, incomes and ages but different physical characteristics.
Clairemont is dotted with single-family homes on small lots where streets are interrupted by canyons, dead-ends and cul-de-sacs. Errands generally must be done by car because stores, businesses and restaurants are hard to reach on foot.
Normal Heights is densely populated, with a mix a houses, apartments, shops, eateries and other businesses and has a grid pattern of streets that gives walkers a change of scenery or a direct route.
The study will be completed at the summer's end, but early evidence suggests the researchers' theory holds up.
"I don't drive because almost everything is within walking distance," said Hiroshi Miyazaki, a retired Mesa College art teacher who lives in Normal Heights and is part of the study. "Library, grocery stores, post office and banks and that's all I need."
Conversely, Rita Moore, a retired credit clerk who also took part in the study, does errands by car because stores are too far from her home in Clairemont. "Half-mile to get there and half-mile back just for a loaf of bread," Moore said. "I get kind of tired walking up there."
Lately, the theory on walking environment is getting a lot of attention -- and validation.
The American Medical Association says changing the community environment is "the most practical approach to prevent obesity."
The CDC launched the Active Community Environments program three years ago to encourage a partnership between public health officials and transportation and city planning organizations to promote walking and bicycling.
The CDC and the Georgia Institute of Technology are preparing to study walking habits by surveying 8,000 residents in traffic-choked Atlanta, and by outfitting about 500 with satellite-linked gizmos so researchers can study how much they walk and why. It's like the San Diego study, only larger.
In California, Caltrans and the state health department plan to study how many people walk and what would entice them to walk more.
The SDSU study is a small version of what the university's researchers plan to do in Boston and Portland over four years, starting this fall.
The researchers received a $2 million grant from the National Institutes of Health to contrast 32 census tracts in each city, but eliminated San Diego as a location for the more extensive study because it could not offer a community that was "walkable" enough.
SDSU researchers will study 2,400 people using computer software and virtual maps to factor in the number of residents per acre, how close every household is to commerce, and traffic and crime data. They will also look at height and weight, income and ethnicity.
"It allows you to literally analyze how various parts of the environment are related to each other and how that affects behavior," Sallis said. "We think this is going to be an incredibly powerful tool to recognize and understand the root causes of inactivity."
Officials hope that if the study shows a link between community design and health, it could influence land-use planners and developers.
"Physical activity is not yet on the development agenda," Sallis said. "We want developers to have to think about the walkability of their designs and how it is likely to affect the health of the population."
There are some notable exceptions, however.
A few years ago, developers of 4S Ranch, a 2,900-acre master-planned community west of Rancho Bernardo, asked Sallis how to make the area walkable.
"There was a lot of skepticism on whether or not walkable communities were more than just a slogan," said Cynthia Vicknair of CynKat Communications, the firm that invited Sallis to advise the developer. "We wanted to know how to actually create a community that was less dependent on the automobile."
The result: 10 miles of walking and biking trails, three neighborhood parks, four schools, 1,600 acres of protected open space, a library and a traditional town square with shops and restaurants, medical and professional offices, day-care facilities and movie theaters.
The community of 4,715 homes held a grand opening May 6.
Still, nobody is saying walkable communities are a cure-all for obesity.
"There is a reason why McDonald's has said they want a restaurant within four minutes of every house," Sallis said.
Copyright 2001 Union-Tribune Publishing Co.