Obesity cancels out benefits from smoking decline

The effects of increasing obesity are forecast to outweigh any benefits from continued reductions in smoking rates over the next decade, a study predicts. The US study found that if current trends in obesity and smoking rates remained unchanged the average life expectancy would be reduced by almost 9 months. The study authors used height and weight information from the National Health and Nutrition Examination Survey to calculate body-mass index. Smoking trends were obtained from the National Health Interview Survey and the effects of smoking status and BMI on quality of life were estimated using data from the Medical Expenditure Panel Survey. Assuming a continuation of past trends for the next 15 years, 21% of current smokers would quit by 2020, the researchers estimated. Based on this factor alone, life expectancy for the typical 18-year-old would increase 0.31 years, with an extra 0.41 years of quality-adjusted life expectancy. But over the same time frame an estimated 45% of Americans were expected to be obese by 2020 which would reduce life expectancy by 1.02 years and quality-adjusted life expectancy by 1.32 years. The net effect of the two risk factors would be a 0.71-year reduction in life expectancy and 0.91-year drop in quality-adjusted life expectancy, the researchers said. If all U.S. adults became nonsmokers of normal weight by 2020, the life expectancy of an 18-year-old would increase by 3.76 life-years or 5.16 quality-adjusted years, the researchers estimated....