WASHINGTON, DC -- If trends continue, 43 percent of U.S. adults could be classified as obese by 2018, according to a new study. Currently, 31 percent of the adult population is considered obese.

The report, “The Future Cost of Obesity: National and State Estimates of the Impact of Obesity on Direct Health Care Expenses,” also estimates that obesity spending will quadruple to $344 billion by 2018.

The study, based on research by Ken Thorpe, Ph.D., Emory University health care economist, was commissioned by UnitedHealth Foundation, Partnership for Prevention and American Public Health Association in conjunction with their annual “America’s Health Rankings” report.

The report also showed, however, that if obesity rates remain at current levels, the United States would save nearly $200 billion in health care costs.

“At a time when Congress is looking for savings in health care, this data confirms what we already knew: obesity is where the money is,” Thorpe, who also is executive director of the Partnership to Fight Chronic Disease, said in a statement about the report. “Because obesity is related to the onset of so many other illnesses, stopping the growth of obesity in the U.S. is vital not only to our health—but also to the solvency of our health care system.”

The report projects that obesity will surpass 50 percent of the adult population in six states, with an associated increase in obesity-linked health spending of more than $1,600 per person in each of these states:

• Kentucky: 2008 obesity rate of 34.8 percent, 2018 estimated rate of 51.2 percent

• Maryland: 2008 obesity rate of 31.2 percent, 2018 estimated rate of 52.1 percent

• Mississippi: 2008 obesity rate of 37.7 percent, 2018 estimated rate of 52.2 percent

• Ohio: 2008 obesity rate of 33.9 percent, 2018 estimated rate of 50.9 percent

• Oklahoma: 2008 obesity rate of 35.2 percent, 2018 estimated rate of 56.1 percent

• South Dakota: 2008 obesity rate of 32.7 percent, 2018 estimated rate of 50.4 percent

The obesity rate will remain below 35 percent in only four states and the District of Columbia. Despite that, obesity-related health spending will climb to more than $800 per person by 2018 in each state:

• Colorado: 2008 obesity rate of 23.8 percent, 2018 estimated rate of 29.8 percent

• Connecticut: 2008 obesity rate of 26.1 percent, 2018 estimated rate of 33.6 percent

• Massachusetts: 2008 obesity rate of 26 percent, 2018 estimated rate of 33.9 percent

• Virginia: 2008 obesity rate of 30.2 percent, 2018 estimated rate of 33.4 percent

• Washington, DC: 2008 obesity rate of 26.4 percent, 2018 estimated rate of 29.2 percent