Analyzing why Americans have a lower life expectancy when compared to most other developed countries, Harvard researchers used 34 years of data on more than 120,000 health professionals to focus on five lifestyle factors that promote longevity. They found that women and men lived on average 14 years and 12 years longer, respectively, if they had a healthy body weight (between 18.5 and 24.9 BMI), never smoked, exercised at moderate-to-vigorous levels at least 30 minutes a day, ate a healthy diet and drank only moderately (one five-ounce glass of wine for women, two for men).