If you’re listening to us at a reasonable volume, crank that sucker up and drown out the traffic. According to a new study, the sound of all those cars is making you fat.

Researchers in Sweden tracked more than 5,000 people from 1999 to 2006, and found you’re 25 percent more likely to be overweight if you’re exposed to traffic that’s higher than 45 decibels on a regular basis. That’s just LIGHT traffic.

Heavy traffic can be 85 or 90 decibels. The study found that for every five decibels above 45, the size of your waist increases almost a tenth of an inch.

So if you sit in heavy traffic every day, your waistline might be half-an-inch bigger because of it.

The researchers aren’t sure why, but they think it might have to do with how much cortisol your body produces to deal with stress. Basically, the sound of traffic stresses you out, which makes you produce cortisol, and that makes you gain weight.

The study also found that if you’re also exposed to the sound of subways and airplanes on a regular basis, you’re twice as likely to be overweight as someone who’s only exposed to traffic.