An adult living somewhere like Atlanta, with its spread-out suburbs and car-heavy culture, will have a health profile that looks like that of someone who lives in Seattle -- but who is four years older, the study found.
And the culprit seems to be exercise, or the lack of it, the researchers report in the October issue of the journal Public Health.
"This is the first study that analyzes suburban sprawl and a broad range of chronic health conditions," said Roland Sturm, an economist at the Rand Corp.'s Rand Health unit who helped write 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. This probably plays an important role in the health effects we observe."
The differences between city and suburban people held even when Sturm's team took into account factors such as age, economic status, race and the local environment.
"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, another Rand researcher.
There was no link between suburban sprawl and mental health. The RAND team found no differences in the rates of depression, anxiety and psychological well-being between people living in downtown areas and those in suburbs.
The Rand team looked at a survey of 8,600 people funded by the Robert Wood Johnson Foundation. These people, living in 38 metropolitan areas across the country, were asked a variety of questions about their health and well-being in 1998 and 2001.
It defined sprawling suburban areas as those with poorly connected streets such as cul-de-sacs, separated areas for schools, housing and shops and a lower population density.
The most extreme examples included the Riverside-San Bernardino region of California, Atlanta and Winston-Salem, North Carolina.
Dense urban areas where people lived close to each other and the schools
and shops included New York City, San Francisco and Boston.