PHOENIX - State health officials say they always have suspected the chances of Arizonans being overweight is directly linked to where they live and the value of their homes.

Now they have proof.

A new study published by the University of Washington found a direct correlation between obesity and ZIP codes and property values. It specifically showed that each $100,000 increase in the median price of a home in a given ZIP code resulted in a 2 percent decrease in obesity rates.

Frances Kaplan, manager of the Nutrition and Physical Activity Program for the Arizona Department of Health Services, said her agency targets some anti-obesity programs at residents of areas of the state with the lowest property values - and, presumably, with the lowest income. She said that is based on the understanding of the link between poverty and being overweight.

In fact, the department specifically chose two Phoenix ZIP codes for a new program aimed at tweens - children age 9 to 12 - t try to get them to lead healthier lives.

"We're really trying to reach people where they live, work or play,'' she said.

Kaplan said the connection between income and obesity is linked to several factors.

For example, Kaplan said department staffers found grocery and convenience stores in the less affluent parts of a community are less likely to stock a full array of healthy food choices. The result, she said, is people end up buying what's available - items Kaplan said are more likely to be convenient but less likely to be good choices.

But changing that, she conceded, is not simple, as stores may simply be buying the items that reflect the choices of the people who shop there. Kaplan said health department workers are hoping to educate customers while trying to convince store owners t increase their choices.

Kaplan said, though, it's not entirely a question of what goes into the body.

"Residents in poor neighborhoods or low-income neighborhoods really have less opportunity to be physically active,'' she said.

The reason? "They don't live in safe neighborhoods.''

Some of that is just the ability to feel safe while out walking or jogging. But Kaplan said it goes beyond that to having safe playgrounds for children.

But some issues, like genetics, transcend economics.

Kaplan cited the tendency of members of the Tohono O'odham Nation and the closely related Pima tribe to be overweight and have diabetes, particularly those who live on this side of the border and who have adopted U.S. lifestyle and eating habits. She said that has led to efforts to work with local organizations to bring back "traditional foods.''

Of particular interest are tepary beans "which are low on the glycemic index and they're very healthy for many reasons.''

She said local projects are again making these beans available, both for purchase as food as well as for planting. Now, Kaplan said, tribal members need to be educated on the preparation and use of these traditional foods.

Adam Drewnowski, director of the University of Washington's Center for Obesity Research, said the study done in King County where Seattle is located, found that obesity rates reached 3 percent in the areas with the lowest property values but wer just 5 percent in more affluent ZIP codes.

Drewnowski also concluded, as has Kaplan, that area prosperity is a good indicator of access to healthy foods and opportunities for exercise.