The advocacy group, Trust for America's Health, said data from the Centers for Disease Control and Prevention showed that the percentage of obese adults for 2002-04 stood at 22.7 percent nationally. The percentage for the previous cycle, 2001-03, was 22 percent.
Alabama had the unhealthiest increase. There, the rate increased 1.5 percentage points to 27.7 percent. Oregon's rate held steady at 21 percent.
The report said the states with the highest percentage of obese adults are Mississippi, Alabama, West Virginia, Louisiana and Tennessee.
The states with the lowest percentage of obese adults are Colorado, Massachusetts, Rhode Island, Connecticut, Vermont and Montana. Hawaii was not included in the report.
While certain regions of the country fared worse than others, particularly the Southeast, the organization said that no state meets the federal government's goal of a 15 percent obesity rate for adults by 2010.
"Bulging waistlines are growing and it's going to cost taxpayers more dollars regardless of where you live," said Shelley Hearne, executive director of the Trust for America's Health.
Hearne said the United States is stuck in a "debate limbo" about how the government should confront obesity. She used the report to call for more government action on several fronts, such as ensuring that land use plans promote physical activity, that school lunch programs serve healthier meals and that Medicaid recipients get access to subsidized fitness programs, such as aerobics classes at the local YMCA.
"We have a crisis of poor nutrition and physical inactivity in the U.S., and it's time we dealt with it," she said.