In a recent study, Kenneth Thorpe, chairman of the department of health policy and management at the Rollins School of Public Health at Emory University, found that if trends continued, annual health care costs related to obesity would total $344 billion by 2018, or more than 20 percent of total health care spending. (It now accounts for 9 percent.) Dr. Thorpe also said that if the incidence of obesity fell to its 1987 level, it would free enough money to cover the nation’s uninsured population.