London, Nov 17 (IANS): Are you obese or overweight? Blame long term exposure to blaring horns and other noise from road traffic, said researchers.

The study showed that a 10 decibel (dB) increase in mean noise level was associated with a 17 per cent increase in obesity.

"Our analysis shows that people exposed to the highest levels of traffic noise are at greater risk of being obese" said Maria Foraster, lead researcher from the Barcelona Institute for Global Health in Spain.

It could be because noise generates stress and affects our sleep. It alters hormone levels and increases blood pressure.

Moreover, among other effects, sleep disturbance deregulates glucose metabolism and alters the appetite, the researchers explained in the paper published in the journal Environment International.

"In the long term, these effects could give rise to chronic physiological alterations, which would explain the proven association between persistent exposure to traffic-related noise and cardiovascular disease or the more recently discovered associations with diabetes and obesity," Foraster said.

"Our findings suggest that reducing traffic-related noise could also be a way of combating the obesity epidemic," he noted.

For the study, the researchers involved 3,796 adults and examined body mass index (BMI), waist circumference, body fat, central obesity and overweight.

They also analysed exposure to noise generated by aircraft and railway traffic and found no significant associations except in the case of long-term exposure to railway noise, which was associated with a higher risk of overweight but not of obesity.