Mississippi became the first state to crack the 30 percent barrier for adult residents considered to be obese. West Virginia and Alabama are just slightly behind, according to the Trust for America's Health, a research group that focuses on disease prevention.
Colorado continued its reign as the leanest state in the nation with an obesity rate projected at 17.6 percent.
This year's report, for the first time, looked at obesity rates among children ages 10 to 17. The District of Columbia had the highest percentage — 22.8 percent. Utah had the lowest percentage of obese youth — 8.5 percent.
Officials at the Trust for America's Health advocate for the government to play a larger role in preventing obesity. People who are overweight are at an increased risk for diabetes, heart problems and other chronic diseases that contribute to greater health care costs.
"It's one of those issues where everyone believes this is an epidemic, but it's not getting the level of political and policymaker attention that it ought to," said Jeffrey Levi, the organization's executive director. "As every candidate for president talks about health care reform and controlling health care cost costs, if we don't hone in on this issue, none of their proposals are going to be affordable."
At the same time, many believe weight is a personal choice and responsibility. Levi doesn't dispute that notion, but he said society can help people make good choices.
"If we want kids to eat healthier food, we have to invest the money for school nutrition programs so that school lunches are healthier," he said. "If we want people to be more physically active, then there have to be safe places to be active. That's not just a class issue. We've designed suburban communities where there are no sidewalks for anybody to go out and take a walk."
To measure obesity rates, Trust for America's Health compares data from 2003-2005 with 2004-2006. It combines data from three years to improve the accuracy of projections. The data come from a survey of height and weight taken over the telephone by state health departments.
Generally, anyone with a body mass index greater than 30 is considered obese. The index is a ratio that takes into account height and weight. The overweight range is 25 to 29.9. Normal is 18.5 to 24.9. People with a large amount of lean muscle mass, such as athletes, can show a large body mass index without having an unhealthy level of fat.
The results of their survey are included in the report, "F as in Fat: How Obesity Policies Are Failing in America," which is available on the organization's Web site, healthyamericans.org