Wasn't this settled?

Eat less, move more, don't smoke. "Combined impact of lifestyle factors on mortality: prospective cohort study in US women," Rob M van Dam, BMJ 2008;337:a1440 Here.

I guess it needed more study. Alcohol consumption was also part of the study, but there are trade offs, depending on the amount. The danger is always that "light" will move on to "excessive," thus eliminating the health benefits.

Conclusions
Avoiding cigarette smoking is of pivotal importance for the prevention of premature death. In our study of middle aged women, adherence to lifestyle guidelines involving a healthy diet, regular physical activity, and weight management was also associated with markedly lower mortality. Of note, our results indicate that a healthy diet and regular physical activity have important health benefits independent of reducing adiposity. These findings underscore the importance of intensifying both efforts to eradicate cigarette smoking and those aimed at improving diet and physical activity.