The population health benefits of a healthy lifestyle: Life expectancy increased and onset of disability delayed.

A key determinant of population health is the behavioral profile of a population. Nearly 80 percent of Americans reach their fifties having smoked cigarettes, been obese, or both. It is unknown to what extent risky behaviors (for example, smoking, having a poor diet, being physically inactive, and consuming an excessive amount of alcohol) collectively are reducing the health and life expectancy of the US population, or what improvements might be achievable in their absence. Using data from the Health and Retirement Study, we studied people ages fifty and older who had never smoked, who were not obese, and who consumed alcohol moderately. Compared to the whole US population, those with such a favorable behavioral profile had a life expectancy at age fifty that was seven years longer, and they experienced a delay in the onset of disability of up to six years. These results provide a benchmark for evaluating the massively damaging effects that behavioral risks have on health at older ages and the importance of prioritizing policies to implement behavioral-based interventions.

http://www.ncbi.nlm.nih.gov/pubmed/28724530?dopt=Abstract