According to a new study, your desk job is making you fat.

Canadian researchers say that sitting at your desk all day may be helping to add extra pounds around your waist." People eat better and exercise more today than they did in the 1970s, yet obesity rates continue to rise," study researcher Carl-Etienne Juneau, of the University of Montreal, said. "And, this contradiction might be explained by changes in work habits." The study found adults took in fewer calories in 2004 than they did in 1972, and leisure-time physical activity rose over a similar time period.

But people have become less active at work over the last three decades, and this decreased activity may partly explain the rise in obesity.