The University of Edinburgh study looked at genetic information from more than 600,000 people and their parents' lifespan records to figure out how different genes and lifestyle choices affect life expectancy. In essence, it's a fresh take on the nature-versus-nurture debate. The study, published in Nature Communications, used data from 25 separate population studies encompassing North America, Europe, and Australia.
People who maintain a healthy weight tend to live longer than those who don't, researchers found, which makes sense. Specifically, overweight people cut their life expectancy by two months for every kilogram (about 2.2lbs) of extra weight they carry, the study suggests. Body fat and factors linked to diabetes also have a negative impact on life expectancy.
But carrying a little extra pudge isn't the worst thing for your longevity—that, unsurprisingly, would be smoking cigarettes. Smoking a pack a day over a lifetime will run you back an average of seven years, but if you give up the habit for good, you can expect to live as long as someone who's never smoked, according to the research.
Living forever may be off the table (for now, anyway), but making these conscious decisions will pay off later. So if you smoke you might want to figure out a way to kick the habit, and if you're a regular couch potato you might want to get motivated and hit the gym hard.