WASHINGTON — While childhood obesity rates in the U.S. appear to be stabilizing, the rate among adults remains stubbornly high, reaching new peaks in several states over the past year.That’s according to the latest annual report on obesity in America published Thursday by the Trust for America’s Health, a health advocacy and research group, and the Robert Wood Johnson Foundation, a philanthropy focused on public health issues. Using federal health data, the report stressed that geography and social factors, like income and race, continue to play a significant role in obesity. The result is that more Americans face a higher risk for health problems, including heart disease, diabetes, some forms of cancers and premature death. “While we’ve seen some progress on the childhood obesity front, the progress is more mixed for adults,” said Jeffrey Levi, executive director of the trust. He said that no state significantly improved over last year and showed a lower obesity rate, “when that’s the ultimate goal here.”Mississippi and West Virginia topped the list as the heaviest states, with their adult obesity rates at 35.1 percent, more than one-third of the population. That’s the first time any state has passed the 35 percent threshold, the report stated. Kentucky, Arkansas and Tennessee rounded out the top five. Colorado had the lowest rate of adult obesity at 21.3 percent, with Hawaii and Massachusetts close behind. However, all 50 states have seen obesity grow as a public health concern over the decades.In 1991, no state had hit the 20 percent mark that even the skinniest states have since passed, the report noted. Though Colorado can now boast of having the lowest level of overweight people in the nation, its rate has more than doubled from two decades ago, when it was just 10 percent, according to the federal Centers for Disease Control and Prevention.“We’ve had a front-row seat to the toll the obesity epidemic has taken on the country, both in terms in health and economic costs,” Levi said.Six states _ Alaska, Delaware, Idaho, New Jersey, Tennessee and Wyoming _ saw statistically significant increases in their rates from last year, ranging from 1.7 percentage points to 4.2 percentage points. Only Arkansas experienced such an increase in last year’s report, with its obesity rate climbing from 30.9 percent in 2011 to 34.5 percent 2012. “It’s disappointing that we saw the numbers increase, but we understand that the battle against obesity is a tough one,” said Angie Gribble, the Idaho Department of Health and Welfare’s physical activity and nutrition program manager.Idaho’s obesity rate was just shy of 30 percent.“There are a lot of things in our day-to-day lives and communities that make it difficult for people to make healthy choices,” she said. Obesity is defined as having a body mass index of 30 or more, while a BMI of 25 to 29.9 is classified as overweight, according to the CDC, whose data was used for the report.Ginny Ehrlich, who directs the foundation’s efforts on childhood obesity, emphasized focusing on prevention in a child’s formative years. “Among children, we’re seeing important declines, particularly among preschool-age kids,” she said.Childhood obesity rates have more than tripled since 1980, although rates have remained the same for the past 10 years, the report said. About 17 percent of children ages 2 to 19 are obese. But the ethnic and racial disparities are particularly pronounced: Among Hispanics in that age group, the rate was 22.4 percent; among blacks, 20.2 percent; among whites, 14.1.Levi said the report’s most concerning finding was further increases in obesity rates for Americans ages 45 to 64, who have the highest rates of all age groups. “The much higher level of obesity among boomers is disconcerting on multiple levels, including both the quality of life and the health care costs this may mean ultimately for the Medicare system,” Levi said.The report said geography still plays a part in obesity rate disparities. Nine of the 10 most obese states are in the South, according to the report. “There are very real differences between communities when it comes to peoples’ access to affordable, healthy foods and safe places to be physically active,” Ehrlich said.Gribble said Idaho’s large size and low population density can hurt efforts against obesity.“There’s very few large population centers, and we know that’s where a lot of the resources and access to care and facilities are high,” Gribble said. “But when the majority of the state is rural, they lack some of that access.”Alaska and Wyoming, who both saw increased obesity rates, have even lower population and population density rates than Idaho. Corey Wiggins, director of the Mississippi Economic Policy Center, said states like Mississippi still struggle with health disparities along racial and socioeconomic lines because of their political and historical past. Wiggins said shared-use agreements between local school districts and community organizations can open up access of recreational space on school property to the public. Wiggins said communities must take ownership and cooperate with local organizations to promote a healthy lifestyle from a young age. “We cannot allow the conversation about reducing childhood obesity to be a conversation that happens only in academia, only in non-profits and only in advocacy,” Wiggins said.