A study published in the December 3rd issue of the New England Journal of Medicine shows that the increasing rate of obesity will have a stronger, more pronounced effect on life expectancy than smoking in years to come. Researchers used data to forecast both the life expectancy and quality-adjusted life expectancy for a representative 18 year old. The smoking data used was gathered from 4 samples taken from the National Health Interview Survey from 1978 to 2006 and showed a 1.4% average decrease in smoking rates in the 15 years prior to 2005. During that same period of time, data measuring Body Mass Index (BMI) from the National Health and Nutrition Examination Surveys (NHANES) from 1971 to 2006 showed a 0.6% average increase. Assuming that those trends continue at a consistent pace for the next 15 years, life expectancy for an average 18 year old will increase 0.31 years (0.41 years of quality-adjusted life expectancy) due to the decreased rate of smoking. Over that same 15 year period, the same average 18 year old will see their life expectancy decrease 1.02 years (1.32 years of quality-adjusted life expectancy) due to rising rates of obesity. By 2020 the normal weight population in the United State is predicted to drop 35% while an estimated 45% of Americans will be obese. “We know that the effects of obesity are not quite as intense as the effects of smoking, but obesity is more widespread,” said Susan T. Stewart, PhD (Harvard) and Director of the private non-profit National Bureau of Economic Research in Cambridge, MA. She went on to add that “if we were to put the same kind of effort into addressing obesity as we have fairly successfully put into addressing smoking, then perhaps we could have the same kind of positive effects for the future.” While most likely an achievable goal, if somehow both obesity and smoking could be eliminated there would be an increase in life expectancy of at least 3.76 years while quality-adjusted life expectancy would rise 5.16 years. (New England Journal of Medicine, 2009).