The price of obesity is starting to add up for many employers in added benefits and absentee costs—especially for women, according to a U.S. study from George Washington University in Washington, D.C.

Researchers examined several factors, including employee sick days, lost productivity and even the need for extra gasoline. They found that the annual cost of being obese is $4,879 for a woman and $2,646 for a man.

It’s much more than the price of being merely overweight, which was estimated at $524 for women and $432 for men.

Larger women tend to earn less than slimmer women, according to recent studies, while wages don’t differ much for men of various sizes.

Obesity rates are steadily on the rise in North America and they’re having a stark effect on the global economy, according to a new report from the Organisation for Economic Co-operation and Development (OECD), Obesity and the Economics of Prevention: Fit not Fat.

“Policy-makers, health professionals and academics all face challenges in understanding the epidemic and devising effective counter-strategies,” the OECD report said.

Among its recommendations, the OECD authors suggest that aggressive implementation of prevention programs could help reduce waistlines and improve bottom lines at many workplaces.

Looking at the price tag may help policy-makers weigh the value of spending to prevent and fight obesity.

“We’re paying a very high price as a society for obesity, and why don’t we think about it as a problem of enormous magnitude to our economy?” asked Dr. Kevin Schulman, a health economist at Duke University in Durham, N.C.

Another major U.S. study published in 2009 revealed that medical spending averages $1,400 more a year for the obese than normal-weight people. The recent George Washington report added mostly work-related costs, such as sick days and disability claims, arising from those weight-related problems.

It also included data that indicated nearly one billion additional gallons (4.5 billion litres) of gasoline are used every year because of increases in car passengers’ weight since 1960.