(CNN) -- While most Americans continue to get fatter, Coloradans stand out as being among the fittest in the country, the Trust for America's Health says.
Exercise and good nutrition are part of the Colorado public consciouness, says one former official.
The state ranked 51st in obesity, with 17.6 percent of its 4.3 million residents squeezing into that category. (The rankings included the District of Columbia.)
And fewer than one in five state residents leads an inactive lifestyle, the trust found.
That appeared to pay off in health benefits, with Colorado ranking 50th in diabetes and high blood pressure.
These figures did not surprise Spenser Havlick, former deputy mayor of Boulder, where exercise and good nutrition rank high in the public consciousness and attract like-minded people from other parts of the country, he said.
"They are leaving behind a more sedentary life in the larger cities," he said. "Every weekend, there's a 5K race, a 10K race; there are ultramarathons."
A number of organic health food stores dot the city, and organic produce "is pushed throughout the schools," he said.
Boulder's 100,000 residents have 360 miles of bike paths and 64 underpasses, so cyclists need not stop when they reach an intersection.
"We think that's much safer, and it's much faster and it's more fun," said Havlick, 72, who returned last week from hiking on glaciers in Alaska.
Exercise is also part of the political culture of Boulder, where seven of the nine City Council members are bicyclists, said Havlick, professor emeritus of architecture and planning at the University of Colorado.
"There's a strong inclination for more money to be spent on reducing car dependency."
Weather, too, plays a role, with 330 days of sunshine, he said.
And social pressure may have an impact. "I think there is a stigma attached to people who have a BMI that's high," he said, referring to body mass index, a measure of body fat based on height and weight.
Still, he noted, the percentage of obese Coloradans has gone up slightly in the past two years. "Some of the folks who come to Colorado to work may not have picked up on these healthy lifestyles yet," he said. E-mail to a friend
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