Everyone knows what a couch potato is, but have you heard of a desk potato? As the American workplace has shifted from farms and factories to cubicles and computer desks, we’re burning fewer calories each day on the job than workers did in the 1960s. That’s according to a new study in the Public Library of Science ONE journal.

Inactivity at work can be just as detrimental to your health – and your pant size – as being sedentary at home. Compared with 50 years ago, American workers are burning between 124 and 142 fewer calories per work day. Left unaccounted for, that caloric surplus adds up to between 9 and 10 pounds of fat gained every year – without eating a single extra dessert.

Speaking to USA Today, one of the study’s lead researchers put the results in a nutshell:

"The jobs requiring moderate physical activity have all but disappeared," says Timothy Church, the study's lead author. He is director of preventive medicine research at the Pennington Biomedical Research Center in Baton Rouge.

"We have transitioned from jobs that primarily involved doing physical activity on our feet to ones where most of us make our living while sitting," he says.

As we explored in our landmark book Small Choices, Big Bodies, being sedentary on the job isn’t the only factor in weight control. Even small modern conveniences like washing machines and air conditioning have consequences for Americans’ daily caloric expenditure. Taken as a whole, reliance on these labor-saving devices easily explains why Americans have gained so much weight in the past 50 years.

There is a way to reverse the trend, however. Add activity back into your work day by adding a short walk on your lunch break. Break a sweat while spending quality time with your friends and family. Opt to take the stairs instead of an elevator every once in a while. Eat your favorite treats in moderation.

Make enough small changes to offset the luxuries of modern living and you won’t even have to give up your laptop or central air to keep your waistline trim.