The full study cautions that these findings do not apply to individuals, each of whom has a personal health history.

Of course, if enough individuals made positive changes at the same time, there would be a social benefit.

Also, the full study is not predicting a decline in life expectancy. It is predicting that it will go up more slowly than it would were obesity not such a serious health problem.

Medpage Today

“Gains in life expectancy from lower smoking rates over the next decade will be offset, to some degree, by reductions in life expectancy based on the rise in obesity, researchers estimated.

“If obesity and smoking rates had held steady, the average 18-year-old would have seen a 2.98-year increase in life expectancy over a 15-year period, according to Susan T. Stewart, PhD, of Harvard and the private nonprofit National Bureau of Economic Research in Cambridge, Mass., and colleagues.

“But a 48% rise in obesity overrode the expected gain from a 20% reduction in smoking rates seen over the past 15 years, the researchers reported in the Dec. 3 New England Journal of Medicine.” (Emphasis added)

Source: Medpage Today, December 2, 2009

Citation: N Engl J Med 2009; 361: 2252-60.