While obesity rates among U.S. adults are remaining steady, they are still high in most areas of the country, with more than 30 percent of adults in 25 states classified as obese, new figures show.

In total, more than a third of adults and 17 percent of children in the U.S. are obese, data released by the U.S. Centers for Disease Control and Prevention indicate.

And more than two-thirds of U.S adults are either obese or overweight, the agency says.

A survey conducted in all 50 states found that obesity rates remained essentially the same in 45 U.S. states, with small increases being noted in Minnesota, Kansas, New Mexico, Utah and Ohio.

The states with the highest rates were mostly in the Midwest and the South, with three states – Arkansas, West Virginia and Mississippi – reporting obesity rates above 35 percent.

Hawaii, the District of Columbia and Colorado had the lowest rates, with Colorado reporting the lowest rate in the U.S. at 21.3 percent.

The CDC gathered the data as part of its Behavior Risk Factor Surveillance System.

"We're seeing some regional differences and that provides us a chance to ... see what's going on at the state level, and do some comparisons there," says Jeff Levi, executive director of the nonprofit Trust for America's Health.

The new figures compare with data from 1980, which found no states with an obesity rate higher than 15 percent, and 1991 when the highest rate in any state was 20 percent, says the Trust and the Robert Wood Johnson Foundation, which analyzed the data released by the CDC.

"Obesity puts some 78 million Americans at an increased risk for a range of health problems, including heart disease, diabetes and cancer," the two groups say in a joint report, State of Obesity: Better Polices for a Healthier America. "Obesity is one of the biggest health care cost drivers – adding up to billions of dollars in preventable spending each year."

The Unites States spends $147 billion a year on obesity-related health issues.

Combating the obesity issue presents a numbers of challenges, Levi says.

"Success requires finding ways to make healthy choices easier in our daily lives," he says. "Children need the chance to grow up at a healthy weight, and all adults need the opportunity to be as healthy as they can be, no matter what their weight."

"We do know a lot about what works, now we just have to invest in these approaches," he concluded.