A study by Cornell University in the January issue of Journal of Health Economics found that an obese person incurs medical costs $2,741 (in 2005 dollars) more than if they were not obese. Across the nation, that adds up to $190.2 billion a year, or 20.6% of national health expenditures. Previous estimates put the cost of obesity at $85.7 billion, or 9.1% of national health expenditures. “Historically we’ve been underestimating the benefit of preventing and reducing obesity,” said lead author John Cawley. The study used a federal survey of 24,000 non-elderly U.S. adults, their doctors, and other medical care providers from 2000 to 2005. The data include the individuals’ weight and height, and two years of their medical care and its cost.