Waistlines across Georgia and the nation continue to expand, though efforts to battle the obesity epidemic are starting to slow its growth.

The Peach State, along with six others, has doubled its obesity rate in the past 15 years -- with the rate hitting 28.7 percent last year, according to a report released Thursday by the nonprofit Trust for America’s Health and Robert Wood Johnson Foundation.

Obesity rates in the South -- home to nine of the top 10 states -- reflect a growing national epidemic that is taxing an already strained health care system, experts say.

People are eating too much of the wrong food and are less active, said Jeff Levi, executive director of the Trust for America’s Health.

“If we’re going to turn around these trends, will power alone won’t do it,” he said.

Nationwide, obesity rates currently surpass 25 percent in more than two-thirds of states, while 20 years ago no state had an obesity rate above 15 percent, the report shows.

Georgia has climbed from having the 34th highest obesity rate in 1995, at 13.8 percent, to No. 17 in 2010, the report shows. Overall, nearly two-thirds of Georgians are defined as overweight or obese, based on weight-to-height ratios.

At the same time, the most recent statistics show 16 states saw significant year-to-year increases in obesity rates, compared with more than 30 in years past, said James Marks, senior vice president of the Robert Wood Johnson Foundation. That’s in part because of states’ efforts to establish farm-to-school programs and other anti-obesity programs, Marks said.

Rising obesity rates have also led to more cases of diabetes, hypertension and other costly, obesity-related chronic illnesses, experts say. In Georgia, obesity costs an estimated $2 billion in medical bills, lost productivity, disability and death, according to state estimates.

The state’s soaring diabetes rate is alarming, said Catherine Davis, a professor of pediatrics at Georgia Health Sciences University. The state posted the fifth largest rise in diabetes rates from 1995 to 2010, according to the study.

“Diabetes is such a destructive disease, and it just slowly ruins every system in the body,” Davis said. “Medical costs are going to spiral out of control, more than they already have.”

The South’s high obesity rates stem partly from high poverty rates, Levi said. People with lower incomes often have less access to grocery stores that carry fresh fruits and vegetables or buy more processed, high calorie food that is cheaper, he said.

Nationally, obesity rates in children have tripled in the past 30 years, according to the Centers for Disease Control.

States and employers are ramping up efforts to fight the epidemic.

Some 20 states, not including Georgia, now have school meal standards that are stricter than the U.S. Department of Agriculture requirements. Only four did seven years ago, the study shows. In Georgia, students across the state will receive annual fitness assessments starting this coming school year as part of Gov. Nathan Deal’s new SHAPE initiative. The program is expected to reach up to 1 million children.

Companies are offering disease and lifestyle management programs aimed at helping workers stay healthy and those with chronic illnesses manage their diseases, said Tony Holmes, a partner in the Atlanta office of global consulting firm Mercer.

While companies are getting more aggressive, he said, “there’s a long way to go.”