The nations with the longest life expectancies include:

Where does the United States come in?

Americans will only add about a year to their lives in 2040, bringing the average lifespan to 79.8. In 2016, Americans lived to roughly 78.7 years, on average. This drops our country's rank to 64 from 43 in 2016.

Additionally, the team determined the top factors contributing to premature mortality: high blood pressure, body mass index and blood sugar as well as tobacco and alcohol use.

Of course, there is no way to ensure you lead a long life, but studies have identified five healthy habits that could help you live longer. As MensHealth.com previously reported, not smoking, maintaining a healthy weight, exercising, minimizing binge drinking and trading junk food for vegetables could add up to 12 years to your life.