PORTLAND, Ore. — To shed the pounds that crept around her waistline, Linda Ginenthal began riding her bike to work — an easy 31/2-mile trip.
It’s not a marathon, nor is it a grueling hike. Yet diet experts say it’s the kind of daily activity that could hold the secret to why Oregon is the only state in the nation where the obesity rate did not increase in the past year.
According to a study released Tuesday by the Washington, D.C.-based Trust for America’s Health, the percentage of overweight Oregonians held steady at 21 percent last year, a sharp contrast to Alabama, where the rate of obesity increased 1.5 percentage points to 27.7 percent.
What makes Oregon different is its emphasis on urban design, which encourages outdoor activities like biking to work, the study’s authors said.
Ten percent of Portland residents pedal to the office on a system of bike paths that crisscross the city like arteries, just as they do in Boulder — another bike-friendly metropolis, located in the leanest state in the nation. Only 16.4 percent of Coloradans are obese, according to the study.
“The solution to obesity is not that everyone should run a marathon,” said Michael Earls, co-author of the study. “It’s the little things that begin to make a dent in the problem, like taking the stairs instead of the elevator or riding your bike to work.”
If a city or town is built in such a way that it forces residents to drive long distances, instead of walking or cycling, then physical activity becomes something that has to be planned rather than an activity which can be woven into the fabric of everyday life, he said.
Obesity expert Tom Farley, the author of “Prescription for a Healthy Nation,” said research in the field has moved away from the notion of personal responsibility to the idea of creating environments that foster healthy living.
“Physical activity has been engineered out of our world,” he said. “It should be natural and normal to be physically active, instead of having to go to the gym.”
For Ginenthal, Portland’s layout has made it convenient for her to ride to work following a familiar path of arching trees. Moreover, her employer, the City of Portland, provides financial incentives, such as a $25 bonus each month for riding her bike to work at least 80 percent of the time.
“It means I get 45 minutes of activity every single day without even thinking about it,” said Ginenthal, who dropped 25 pounds since she began riding to work in the 1990s.
Another factor that might explain Oregon’s stagnant obesity rate is healthier eating. According to the U.S. Department of Agriculture, the number of farms in Oregon increased by about 50 percent from 1974 to 2002, a period when many farms across the country were going up on the auction block.
As a result, Oregon’s cities have seen a mushrooming of farmer’s markets — “from just one tiny Saturday market tucked away in a corner of Portland, to one for practically every day of the week,” said organic farmer Shari Raider, who delivers a bounty of fresh greens to area restaurants.
The study, however, has its critics, including state epidemiologist Melvin Kohn, who said that while the findings look impressive on paper, nearly 59 percent of adult Oregonians are classified as either “obese” or “overweight.”
“That’s almost two-thirds of Oregonians,” said Kohn. “I don’t think we can rest on our laurels and say we don’t have a problem.”
And others say that the study — which compared two three-year intervals, 2001 through 2003 and 2002 through 2004 — is not long enough to be significant.
The obesity rate in neighboring Washington is 21.7 percent, up 1 percentage point, according to the survey.