Gaining just a few pounds can shave 7 months off your life

Here’s one more reason you should ward off that extra weight: Carrying extra pounds can cut a significant amount of time off your life, a new study published in Nature Communications discovered.

In the study, researchers analyzed genetic information from more than 600,000 people and checked them against records of their parents’ lifespans. This allowed the team to figure out which genes played a role in life expectancy—and the extent to which they did so.

Once they figured out the genetic components influencing lifespan, they were able to delve into which controllable lifestyle factors played a role.

Their findings? Weight gain was a big one: For every one-unit increase in body mass index (BMI), a person’s life expectancy dropped by seven months.

That means a 5’10” guy who weighs 174 pounds and has a BMI of 25 would need to gain just seven pounds to give him a one-unit BMI bump to 26, according to the National Institutes of Health BMI chart.

If he gained another seven pounds, that would give him a two-unit BMI jump to 27, meaning his life expectancy could likely decrease by 14 months.

Another way of looking at it: If you’re overweight—meaning, if you have a BMI of 25 or above—you cut your life expectancy by two months for every 2.2 pounds they carry, the researchers explained in a statement.

Unsurprisingly, they also linked smoking to checking out early. Lifelong smokers who smoke one pack of 20 cigs a day cut their life expectancy by 6.8 years, the study found.

As for protective measures? For each additional year spent studying, people added 11 months to their lives.

Bottom line: This study proves once again that a solid amount of your life expectancy is under your control. So if you want to live longer and are carrying extra weight, that means you have to get serious about your diet and exercise program.

Reducing an overweight BMI by just one unit—again, that’s about seven pounds for a 5’10” man—can add seven months to your life. Want to get started dropping the weight? Try The 21-Day Metashred from Men’s Health—you’ll burn fat while building lean muscle, right in your own home. These 10 nutrition rules will help you lose weight, too.