25 Aug 2010
Amble, stroll or pedal: it's all good. A new study provides evidence supporting a seemingly obvious - but unproven - link between walking- and cycling-friendly communities and lower levels of obesity.
Researchers found that people are more likely to have healthy weights if they live in places where walking and cycling are more common. The link held up among nations, cities and U.S. states.
The research does not prove that living in couch-potato land directly boosts a resident's risk of being fat.
Still, the study findings suggest, "It's really important to promote walking and cycling as safe, convenient and feasible modes of getting around on an everyday basis," said lead author John Pucher, a professor who studies transportation at Rutgers University.
Pucher and colleagues analyzed statistics about walking and cycling for all purposes from 14 countries, including Sweden, Spain and Great Britain. They also looked at statistics about walking and cycling to work (it had to be the main way people got there) in all 50 states and 47 of the 50 largest U.S. cities.
Switzerland, the Netherlands and Spain had the highest levels of walking and cycling among the countries, with the United States in the bottom three with Australia and Canada. Among American cities, the highest rates of walking and cycling to work were in Boston, Washington D.C., San Francisco, Minneapolis and Seattle.
The researchers tried to find links between the levels of walking and cycling and those of physical activity, obesity and diabetes in the geographic areas. Their findings appear in the October issue of the American Journal of Public Health.
There is a connection between more walking and cycling and lower levels of obesity and diabetes, the researchers found. Not surprisingly, they also linked more walking and cycling to higher overall levels of physical activity.
The study does not calculate the overall percentage difference in levels of obesity and diabetes between places with the highest and lowest levels of walking and cycling. Nevertheless, Pucher said readers could calculate those numbers and find other statistics by examining research data.
In the big picture, the study results suggest that a big part of the gaps between American states and cities concerning health can be explained by differences in levels of walking and cycling, Pucher said.
While the link between more exercise and less obesity might seem obvious, he said there is a need for more scientific evidence to back it up. "As obvious as it is," he said, "it's shocking that Americans don't want to do anything about it. It's amazing how unconcerned most Americans are about this."
Lawrence Frank, an associate professor who studies transportation at the University of British Columbia, said the study findings reflect the results of previous research that shows the effects of exercise (or the lack of it) on health.
"Physical activity is crucial," Frank said. "If we keep designing communities in ways that make driving the more rational choice, we can expect health care costs to go up and quality of life to go down."
The American Journal of Public Health is the monthly journal of the American Public Health Association.
Pucher J, et al. Walking and cycling to health: a comparison of recent evidence from city, state, and international studies. Am J Public Health 100(10), 2010.
Health Behavior News Service