Oct. 8, 2010 - The health-related cost of obesity among U.S. workers is $73.1 billion a year -- enough to pay the salaries of 1.8 million new workers.

Surprisingly, most of this cost comes in the form of "presenteeism" -- lost productivity due to poor health, find Eric Finkelstein, PhD, of Duke University and colleagues.

In a study funded by Allergan Inc., which makes a gastric band system for obesity surgery, Finkelstein's team set out to estimate the health-related costs of obesity.

Surprisingly, they found that presenteeism is the major driver of health-related costs to employers -- for all workers, not just those who are obese.

Even for normal weight-workers, the cost of presenteeism is as high as the cost of medical expenditures," Finkelstein tells WebMD. "Even among full-time employees who are normal weight, health problems undermine productivity to a large extent."

In terms of absenteeism (days of work missed), presenteeism (lost productivity due to poor health), and direct medical costs, the annual health cost of a normal-weight employee is about $10,000. But for the most extremely obese workers -- those about 100 pounds overweight -- the cost is about $16,000.

About 37% of the obese population in the U.S. is in the two highest grades of obesity -- a body mass index (BMI) of 35 to 39 and a BMI of 40 or more. But these two groups are responsible for 61% of the costs resulting from excess weight, Finkelstein and colleagues calculate.

 
Presenteeism Major Health Cost

Finkelstein is quick to note that the biggest health-related cost to employers is presenteeism -- and that it's hard to get an exact estimate.

In their study, the researchers used data from the 2008 U.S. National Health and Wellness Survey, a series of self-administered, Internet-based questionnaires fielded to 63,000 members of a nationally representative consumer panel.

People were asked how many days in the past week they were in poor health. They were then asked to estimate, on a 0 to 10 scale, how much their health affected them when they were working. If a person gave an answer of 3 (with zero being fully productive and 10 being not productive at all), the researchers assumed that person was 30% less productive. Days of poor health were then multiplied out to give an annual estimate of presenteeism.

"There are lots of problems with this, but it's a validated scale and it's the best we have," Finkelstein says. "But even if we are off by 50%, these are still big numbers."

The point of the study, Finkelstein says, isn't to blame obese workers. The point is to emphasize to employers the real value of employee health.

"Employers need to be worried about the health of all their employees, not just obese ones," he says. "My hope is this helps everyone, because it creates momentum for governments, schools, and private workplaces to do things that improve everybody's health."

That's not to say people who are extremely obese would not benefit from losing a lot of weight. But workers in this category would benefit even more from the support of their employers.

The Finkelstein study appears in the Sept. 25 online issue of the Journal of Occupational and Environmental Medicine.