It is estimated that obesity accounts for 5 to 15% of deaths each year in the United States and that smoking is responsible for 18% of the nation’s annual deaths. Susan T. Stewart, from Harvard University Interfaculty Program for Health Systems Improvement (Massachusetts, USA), and colleagues forecasted life expectancy and quality-adjusted life expectancy for a representative 18-year-old, for the years 2005 through 2020, assuming continued trends in both smoking and obesity. The team found that the negative effects of increasing body mass index far overwhelmed the positive effects of declines in smoking. The researchers warn that: “If past obesity trends continue unchecked, the negative effects on the health of the U.S. population will increasingly outweigh the positive effects gained from declining smoking rates. Failure to address continued increases in obesity could result in an erosion of the pattern of steady gains in health observed since early in the 20th century.”
