Hawai'i's good weather and large Asian population are again being credited with keeping the state on the low end of the obesity scale nationwide.

The Trust for America's Health, an advocacy group that promotes increased funding for public-health programs, said yesterday that 18.2 percent of Hawai'i's adult population is obese. Only Colorado did better, with an obese population of 16.9 percent. Mississippi had the highest percentage of obese residents, at 29.5 percent.

The group also said that 51.6 percent of Hawai'i's population is overweight or obese, lowest for all states.

Roughly 40 percent of Hawai'i's population is Asian, and those ethnic groups tend to be leaner, said Dr. Jay Maddock of the University of Hawai'i's Department of Public Health Sciences and Epidemiology. Traditional Asian diets include lots of fruit and vegetables and limited meat intake, he said.

Hawai'i residents also are more active than their Mainland counterparts, Maddock said.

"Our year-round good weather definitely gets people outside and moving," he said. "Seems like our kids do get out more than kids on the Mainland, and we have afterschool programs that are keeping kids somewhat active."

DIFFERENT CHALLENGES

The group reported that adult obesity exceeds 25 percent in 13 states. Health officials warn that a high incidence of obesity in a particular state doesn't mean it treats the issue less seriously than others. States have different challenges when it comes to obesity, said Dr. Janet Collins of the Centers for Disease Control and Prevention.

"Populations are not equal in terms of experiencing these health problems," Collins said. "Low-income populations tend to experience all the health problems we worry about at greater rates."

Indeed, the five states with the highest obesity rates — Mississippi, Alabama, West Virginia, Louisiana and Kentucky — exhibit much higher rates of poverty than the national norm.

Meanwhile, the five states with the lowest obesity have less poverty. They are Colorado, Hawai'i, Massachusetts, Rhode Island and Vermont.

In Hawai'i, there are disparities among the multi-ethnic population, with higher rates of obesity, diabetes and hypertension among Native Hawaiians and other Pacific Islanders compared with Caucasians and some Asian groups.

"Hawai'i is all about the ethnic disparities. Overall we do well, but there are ethnic groups that do a lot worse," Maddock said. "Some of it can be explained by the introduction of a Western diet," he said, but there likely are other factors such as genetics. Health officials have yet to fully explore why certain ethnic groups do better or worse than others, Maddock said.

Since poverty appears to be one factor in obesity, the Healthy Hawai'i Initiative plans in October to launch a nutrition campaign targeting families that receive food stamps, said Maddock, who is involved with the initiative. The Department of Health program was started in 2000 with funds from the tobacco industry settlement.

Maddock said previous campaigns to encourage residents to eat more fruit and vegetables and switch to low-fat milk have been successful, perhaps contributing to the state's relatively low obesity rate.

He endorsed one of the recommendations for reducing obesity made by the Trust for America's Health: that local governments approve zoning and land-use laws that give people more chances to walk or bike to the store or to work.

"We need to change the environment to make it easier for people to be active, especially on the Neighbor Islands where you see many new developments with no sidewalks. We are engineering physical activity out of our daily lives because of land-use policies," he said.

BODY MASS INDEX

The advocacy group's estimate of obesity rates is based on a three-year average, 2003 to 2005. The data come from an annual random sampling of adults via the telephone.

The government equates obesity with a body mass index, or BMI, of at least 30. Someone who is 5 feet 4 would have to weigh 175 pounds to reach that threshold. For some people, particularly athletes who exercise a great deal, the BMI could show them as being obese when in fact they are in excellent physical condition.

Some research has shown that individuals of Polynesian ancestry may have less body fat and more lean muscle mass, suggesting that these groups should have higher baseline BMIs from which to determine overweight and obesity. And despite "healthy" BMIs, research has shown that some Asian groups have a high risk of weight-related health problems.