Planning magazine — June 2001

Fat City

Are we building sick communities?

By Christine Kreyling

Fat cities make people fat — or so the current research seems to say. One result is that planners are being asked to consider the links between collective sprawl and individual spread — that is, the physical health consequences of land-use and transportation plans.

"We're picking up where the planning profession started," says Robert Yaro, the executive director of the Regional Plan Association of New York.

"Eighty years ago, when RPA was founded to develop a long-range plan for the greater New York region, it was because of public health concerns," Yaro notes. "Now the issue is the chronic diseases related to obesity and inactivity levels, which are related to auto-dependency — type two diabetes, hypertension, heart disease — that are putting the population of the whole country at risk. It's a situation worthy of a bumper sticker: The suburbs are bad for your health."

Busting out all over

Obesity and its connection to the built environment is a concern at the Centers for Disease Control and Prevention (CDC), the Atlanta-based arm of the federal government charged with the nation's public health. In the October 27, 1999 issue of the Journal of the American Medical Association, the CDC reports that by 1998, nearly one in five adult Americans weighed at least 30 percent over their ideal weight — an increase from one in eight adults just seven years earlier. The increase happened across the board: all states, age groups, races, education levels, and both sexes registered the weight gain.

The CDC compiled its findings via the Behavioral Risk Factor Surveillance System, in which each state conducts annual phone surveys on the leading health indicators of its citizens and then reports the data to the CDC. Because each interviewee reports his or her own weight and height and people tend to underestimate their poundage, CDC researchers suspect that the actual degree of obesity in the U.S. may be even higher.

The highest increases in obesity, according to the CDC report, occurred among 18-to-29 year olds, people with some college education, and people of Hispanic heritage. The region that grew fatter fastest was the South, with a 67 percent rise in the number of obese residents.

"Overweight and physical inactivity account for more than 300,000 premature deaths each year in the U.S., second only to tobacco-related deaths," says Jeffrey Koplan, CDC director and one of the authors of the JAMA article. "Obesity and overweight are linked to the nation's number one killer — heart disease — as well as diabetes and other chronic conditions."

Further, CDC research shows that 60 percent of overweight five-to-10-year-old children already have at least one risk factor for chronic disease: elevated fats in the bloodstream, elevated blood pressure, or high insulin levels.

Dr. Bree Andrews, of Chicago's Children's Memorial Hospital, does research on sedentary children and worries about the rising tide of type two diabetes (formerly called adult onset diabetes). "This is the kind of obesity-related diabetes whose effects — amputations, cardiovascular disease, organ damage — are major. That it's showing up at much earlier ages means that the damage will also show up earlier in the lifespan," Andrews says.

Move it and lose it

The key variables in preventing obesity are calories consumed and calories expended. CDC surveys conducted in 1994 — 96 and 1997 — 98 found that Americans were consuming more calories than ever but finding fewer ways to burn them off. According to the CDC, the culprits include automated workplaces, labor-saving devices for household chores, television viewing, and the fact that auto travel has largely replaced walking and biking.

"From focus groups we've conducted," says Richard Killingsworth, a health scientist at the CDC, "we've found that people have little opportunity to walk in their neighborhoods, or from their homes to stores or recreation. And children don't have the opportunity to walk to school."

According to the Surgeon General's 1996 report, "Physical Activity and Health," more than 60 percent of American adults are not regularly physically active.

The report concludes that "Americans can substantially improve their health and quality of life by including moderate amounts of physical activity in their daily lives." Examples include 30 minutes of brisk walking, lawn mowing, or raking leaves, preferably five days a week.

"The health club approach [to curbing obesity] has never been successful, nor will it," says Killingsworth. But, he adds, the flip side is that we must make it socially acceptable and practical to walk or pedal to a destination.

It's the land use, Scarlett

Anyone familiar with Federal Highway Administration statistics knows that Americans are driving more miles and making more trips than ever before. A 1999 report by the Surface Transportation Policy Project (STPP) of Washington, D.C., "High Mileage Moms," notes, "Overall, drivers spent 43 more hours per year in their cars in 1995 than they did in 1990 — an 11 percent increase in just five years."

STPP focused on the gender differences in driving, and found that women drive more — a daily average of five trips, covering 29 miles, and taking more than an hour — because they are often the sole transportation providers for children and elderly parents who cannot drive and have few other transportation options.

Of equal import are the purposes for driving. "The commute to work is no longer the focal point of the day's travel," the STPP report states. "Going to work now accounts for only 18 percent of the average American's trips, whereas shopping, chauffeuring, and conducting other errands accounts for 46 percent of trips."

Where does the fault lie? STPP says it "lies in the way we've built our communities," as places where children must be chauffeured and where shops, schools, and homes are so spread out that numerous and increasingly lengthy trips are needed to accomplish the tasks of daily life.

Those who see a link between obesity and low-density development note that the South, where the CDC found the greatest increase in obesity in the 1990s, also experienced the nation's greatest increase in suburban — as opposed to urban — population. According to an analysis of U.S. Census Bureau figures published last month in the New York Times, the South's population became more than 19 percent more suburban in the 1990s, following a 30 percent suburban increase in the 1980s.

And as other research shows, suburban development often discourages walking. In "Mean Streets 2000," a report issued last year, STPP calculated fatalities against U.S. Census Bureau figures for pedestrian activity in a given metro region. It concluded that "walking tends to be most dangerous in newer Southern and Western metro areas" where sprawling development patterns are more prominent.

"Intersections are often designed with wide sweeping curves that allow cars to keep moving at high speed, but increase the crossing distance and danger for pedestrians," according to the Mean Streets report. "Zoning codes typically require businesses to be fronted by a large parking lot, forcing pedestrians to thread their way through a maze of parked cars to reach their destination."

It's no wonder that the number of trips people take on foot has declined by 42 percent in the last 20 years.

Doing the homework

There is much circumstantial evidence, but little hard data, on the effects that density, land-use mixture, and street connectivity have on household activity patterns. A variety of disciplines are coming together to fill the data gap.

Lawrence Frank, AICP, an assistant professor in the Georgia Institute of Technology's Graduate City Planning Program, studied the relationship between the age of residential development in the Seattle region and the number and modes of trips made from the home. Working with 1996 data from the Puget Sound Transportation Panel, a survey conducted by the Puget Sound Regional Council, Frank found that residents of newer developments take more vehicle trips.

Frank's research showed that people living in communities developed before 1947 traveled by foot or bike more than three times every two days. People living in areas developed after 1977 got out of their car barely once in the same period.

Frank is now the principal investigator in a larger study on land use, travel behavior, and public health called SMARTRAQ (Strategies for Metropolitan Atlanta's Regional Transportation and Air Quality).

The main impetus behind the $4.1 million study is the Atlanta region's lack of compliance with federal air quality standards, and the consequent cut-off of federal dollars for roads. SMARTRAQ is a Georgia Tech research project supported by state, federal, and foundation funds as well as the Atlanta Chamber of Commerce and the Urban Land Institute's Atlanta office.

At the heart of the research is a travel study of 8,000 households in the 13 counties of the Atlanta metropolitan region, characterized by the land-use type and density in which the household is located. One sub-survey of 1,500 households will focus on the factors underlying residential preference: Why people choose to live in a particular type of neighborhood.

The public health and physical activity sub-survey, conducted by the CDC in partnership with the Georgia State Department of Health, will study the connection between the way cities are built — low-density pods, traditional neighborhoods, or dense downtowns — and human health. Using the results of a questionnaire provided to 1,000 households, the health scientists will estimate the relative impact of urban form and transportation investment on the overall level of household activity.

The public health research for SMARTRAQ, scheduled to be completed in January 2002, is timely for the Atlanta region. Among all the states, Georgia topped the scales with a 101 percent increase in obese residents between 1990 and 1998.

Cause and effect?

In the last two years, the Robert Wood Johnson Foundation of Princeton, New Jersey, also has begun to look at the non-medical or social determinants of health, especially the impacts of community design and transportation planning, according to Katherine Kraft, the foundation's senior program officer.

This July, the foundation will make grants to communities already involved with smart growth practices in order to create models for other communities to emulate. "I was amazed to discover that people from public health had not previously been involved in these initiatives, that there are 30 state cabinets dedicated to smart growth initiatives, and not one includes its health department," Kraft says. As a result, the foundation is funding a series of seminars to discuss the relationships between health and community design. Also, the foundation has sought the advice of APA's research department on how to get planners and urban designers thinking about the connections between community design and physical activity.

Finally, the foundation is providing four years of research funding to James Sallis, a professor of psychology at San Diego State University. Sallis is bringing together experts from a variety of disciplines, including land use, transportation, and urban design, as well as geography, exercise science, epidemiology, and health psychology, to determine research priorities.

In studying the effects of environment on physical activity, Sallis says he expects to "go beyond the three variables of density, infrastructure, and land-use mixture to such micro-characteristics as the tree cover, aesthetics, and pedestrian safety of sidewalks; whether people use linear parks more than traditional parks; and what's more influential, the actual or perceptual environment."

The foundation also has hired landscape architect Stephanie Bothwell, an expert on livable communities, to work with architects and architectural educators on the issue of physical activity and individual building design. "If you bike to work and there's no place to store your gear, if you walk into a building and the elevator core is front and center and the stairs are dark and dingy and around to the side, you'll probably ride even if it's only for a level or two," Bothwell says.

Reid Ewing, a research professor in the Bloustein School of Planning and Public Policy at Rutgers University, says studies have "pretty much nailed the links between urban form and travel choices and demand." Now he's ready to explore the effects of urban sprawl and transportation choice on public health.

On behalf of Rutgers, CDC, and STPP, Ewing has sent the foundation a research proposal to test hypotheses that obesity, heart disease, and other conditions associated with physical inactivity are more prevalent in metropolitan areas with high sprawl indices and low transportation choice. Ewing's study could provide the macro complement to the micro data being assembled in the SMARTRAQ study.

Just do it

Robert Yaro thinks planners would be unwise to wait until the data are in. "The situation is analogous to global climate change, in that there is already strong circumstantial evidence, if not totally definitive data, that how we design communities and mobility systems impacts activity levels, which impacts obesity, which impacts chronic diseases," Yaro says.

He suggests that "broadening the range of community types beyond the auto-dependent model" would be a good way to respond to changing demographics nationwide. "The boomers will be retiring in the next 10 to 20 years," he says. "Many of them, like me, have grown children, are tired of mowing the lawn, and might find an urban setting more appropriate."

He also points out that the 2000 census predicts the U.S. will add more than 50 million new residents by 2020, and 128 million by 2050. "It seems merely prudent that we organize the next generation of development around healthy principles. To do otherwise would be to shorten our lives and damage our kids' health."

"We're talking about retrofitting existing neighborhoods with sidewalks and traffic calming, and organizing new communities around schools, parks and greenways, and a pedestrian-transit circulation system," he adds. "This already makes good sense economically, socially, aesthetically, environmentally, and for quality of life. Adding the public health rationale of the scientist just gives us a new set of allies and arguments."

Christine Kreyling writes about planning and architecture for the Nashville Scene.