A recent Swedish study has revealed that people who live in noisy areas are more likely to have larger waistlines. Sources of noise covered in the study included trains, planes and automobiles.

The researchers believe that stress caused by the exposure to noise pollution could be partially to blame for the excessive weight of those who were studied. According to the Independent, the research “suggest that traffic noise exposure can increase the risk of central obesity.”

During the study, researchers from Norway and Sweden looked at the level of noise exposure experienced by men and women living in Stockholm. The sample population was also monitored for their body mass index (BMI), waist-to-hip ratio and size of the waist.

Nearly two-thirds of the subjects were exposed to noise greater than 45 decibels (dB). Although researchers found no connection between road traffic noise and BMI, they did notice an increased waistline in people who were exposed to noise levels exceeding 45 dB.

The researchers believe that noise disturbs sleep, and also stimulates the production of cortisol, which may lead to accumulation of fat around the waist and abdomen. “This may explain why the effects of noise were mainly seen for markers of central obesity, such as waist circumference and waist-hip ratio, rather than for generalized obesity, measured by BMI,” the researchers explained.

The study has been published in the Occupational & Environmental Medicine journal.