“This is the first study that analyzes suburban sprawl and a broad range of chronic health conditions,” said Roland Sturm, a RAND Health economist and co-author of the study.

“We know from previous studies that suburban sprawl reduces the time people spend walking and increases the time they spend sitting in cars, and that is associated with higher obesity rates," Sturm explained. "This probably plays an important role in the health effects we observe.”

A more sprawling area has streets that are not well connected (cul-de-sacs rather than grids), more-separated land-use mix (shopping, schools, work and residential areas far from each other), and a lower population density.

People who live in areas with a high degree of suburban sprawl are more likely to report chronic health problems -- such as high blood pressure, arthritis, headaches and breathing difficulties -- than people who live in less-sprawling areas, the researchers found. The differences between people living in the two types of areas remained even when researchers accounted for such factors as age, economic status, race and local environmental conditions.

The findings suggest that an adult who lives in a more-sprawling city, such as Atlanta, will have a health profile similar to someone four years older -- but otherwise similar -- who lives in a more-compact city, such as Seattle.

The study's conclusions are published in the October edition of the journal Public Health, in an article titled, “Suburban Sprawl and Physical and Mental Health.”

“To improve our health, the study suggests that we should build cities where people feel comfortable walking and are not so dependent on cars,” said Deborah Cohen, a Rand researcher and physician who co-authored the study. “This study gives the public a way to personalize the issue of sprawl in a way that hasn’t happened before.”

The unhealthful impacts of suburban sprawl disproportionately affect the poor and the elderly, who often have fewer resources to make up for the limitations created by their environment, researchers found.

In contrast, the study found no link between suburban sprawl and a greater incidence of mental-health problems.

Many researchers have proposed that suburban sprawl results in social isolation that may lead to more mental health problems among suburbanites. But Rand researchers found no differences in the rate of depression, anxiety and psychological well-being among people who live in urban and suburban settings.

The study names the following regions as having the worst suburban sprawl: the Riverside-San Bernardino region of California; Atlanta; Winston-Salem, North Carolina; West Palm Beach, Florida; Bridgeport-Danbury-Stamford, Connecticut; Knoxville, Tennessee; Rochester, New York; and Detroit.

Regions with the least amount of suburban sprawl include the following: New York City; San Francisco; Boston; Portland, Oregon; Miami; Denver; Chicago; and Milwaukee.