After years of astonishing increases, adult obesity rates in the U.S. are showing signs of leveling off for the second year in a row, according to a report released Thursday. But far too many Americans still are too fat, and officials worry that rates could again rise unless programs and policies to address the issue continue.

The 14th annual State of Obesity report from the Trust for America's Health and the Robert Wood Johnson Foundation says that nationally, nearly 38 percent of adults are obese, with nearly eight percent considered extremely obese.

Pennsylvania ranks 25th among states with an overall obesity rate at 30.3 percent, but the rate jumps to 36.4 percent for blacks and 39.5 percent for Latinos as compared to 29.5 for whites. In 2000, the state's overall obesity rate was 20.3, and in 1990 it was 13.7 percent.

New Jersey ranks 36th with an overall adult obesity rate of 27.4 percent (37.2 percent for blacks, 31.4 percent for Latinos, 25.4 percent for whites). In 2000, the overall obesity rate was 17.0 percent, and in 1995 it was 12.3 percent.

The state data, which comes from the Behavioral Risk Factor Surveillance System, relies on people to report their own weights via telephone surveys, so it likely underestimates true rates, the study notes. The national figure, however, comes from another report, the National Health and Nutrition Examination Survey,  which calculates obesity rates based on actual physical examinations, so it's considered a more solid number.

The nation is "at risk of poor health" if programs to address obesity and support for nutritional programs and increased physical activity lose funding, said John Auerbach, president and CEO of the Trust for America's Health. He said the next few years will be crucial if improvements are to continue.

"In 2000, no state had an obesity rate of 25 percent. Now 46 states do," he said. The cost in treating obesity and related illnesses exceeded $150 billion annually, he said. Nearly 30 percent of hypertension cases may be attributable to obesity; diabetes rates have nearly doubled in the past 20 years, the report indicated.

Colorado had the lowest rate at 22.3 percent, and West Virginia had the highest at 37.7 percent, according to the report.

Rates in rural areas of the country are higher. Nine of the states with the highest obesity rates are in the South.

In addition to ethnicity, education and poverty also are factors.

Obesity rates are about 30 percent higher among adults without a college education or who have incomes below $15,000,  the report found.

Twenty-five percent of young adults who try to join the military are ineligible due to concerns about their weight or fitness.

At the same time, overall childhood rates are stabilizing, and in a few places even improving.

"Philadelphia demonstrated that progress can be made on the issue of obesity now," said Don Schwarz, vice president of the Robert Wood Johnson Foundation. Programs to reach out to low-income kids, including gaining access to healthier foods and exercise, helped bring down the rate "disproportionately quickly" in the city, he said.

Both groups recommend continued funding for anti-obesity programs at the federal, state, and local levels including at the Centers for Disease Control and Prevention and Public Health Fund; early childhood programs such as Head Start; and school-based programs and policies that emphasize healthy foods and physical activity. Further, they said, nutritional fact labels should be updated and health-care coverage including Medicare and Medicaid should be expanded to include obesity prevention, treatment, and management.