The health burden of obesity in the United States has overtaken that of smoking, according to a new study examining the relative effects of the two problems on quality of life, mortality and morbidity. More than a third of the nation’s population is now obese, and nearly the same proportion is overweight. Examining the cost of obesity-related diseases often focuses on tax: according to the Institute of Medicine, illnesses such as type-2 diabetes and cardiovascular disease cost the taxpayer $147 billion in 2008. But this latest study, published in the American Journal of Preventive Medicine, examines obesity’s effect on quality of life as well as years of life lost due to the condition. The analysis of 1993-2008 data from the National Health Interview Survey and the Behavioral Risk Factor Surveillance System showed that smoking still had a higher mortality risk than obesity. But by 2008, the obese were losing more quality-adjusted life years through disability and activity limitation. Over the 15-year period, researchers found that smoking decreased by 18.5 percent while the proportion of the population that was obese increased by 85 percent.