Doctors have been preaching for decades about the health risks of obesity.economics-of-fat

Now economists are weighing in, and the numbers are even scarier than the ones on your bathroom scale.

A new study released by the Campaign to End Obesity warns of crippling expenses.

"Our comprehensive review of the literature on this subject suggests that the more we look into the costs of obesity, the more daunting they appear," Michael O'Grady and James Capretta write in "Accessing the Economics of Obesity and Obesity Intervention."

The study authors are no lighweights. O'Grady served as assistant secretary of the U.S. Department of Health and Human Services from 2003 to 2005, and Capretta was associate director of the U.S. Office of Management and Budget from 2001 to 2004.

O'Grady and Capretta conclude that the usual 10-year time window that federal budget experts use to estimate costs and benefits of government programs is too short because the impacts of obesity take longer to manifest themselves. They recommend a 25-year forecasting window.

Why should the federal government care if we're fat?

Obesity is associated with development of chronic conditions, such as diabetes, heart disease and high blood pressure, and those conditions are expensive to treat. As Americans get fatter, costs grow for taxpayer-financed programs, such as Medicare and Medicaid, as well as for private health insurance plans.

The cost of obesity in 2008 amounted to $147 billion, or 10 percent of all medical spending. That's according to a 2009 study by the Centers for Disease Control and the Agency for Healthcare Research and Quality.

But based on a review of other studies, O'Grady and Capretta say costs could be even higher when indirect impacts of obesity are considered, such as lost productivity due to disability.

But some programs to slow the obesity trend show promise. However, the folks who advise policymakers and legislators need sophisticated forecasting models, and they need to look further in the future -- beyond the usual 10 years -- to project the impact of prevention programs. Good forecasting ability is critical for the future of the health care system.

"Controlling obesity has a large enough effect on cost trends that it can make the difference between a health care program being financially viable or financially vulnerable in the long term," the authors write.

Weighty numbers

More than two-thirds of Americans now are overweight or obese. (West Virginians have the highest obesity rate, according to Gallup.) The biggest concern is the growing number of obese and extremely obese people. You're overweight if your body mass index (BMI) is between 25 and 29.9. You're considered obese if your BMI is 30 or more and extremely obese if it's 40 or more. (A 5-foot-9 adult weighing 271 pounds would have a BMI of 40.) Lots of folks are struggling to get their BMI down.

According to the latest figures from the Centers for Disease Control, 34 percent of Americans were obese in 2008 and 6 percent were extremely obese. That's more than double the 13 percent who were obese in 1961 and six times the 1 percent who were extremely obese some 50 years ago.

"People who would have been normal weight in the 1960s are now overweight; people who would have been overweight are now obese, and people who would have been obese are now extremely obese," the study authors write.

If the trend continues, about half of Americans could be obese by 2030. That's an alarming statistic for anyone concerned about affordable health insurance.

"Our research has convinced us that the problem is severe, for both the health of the American people and the financial viability of our health care system," the authors conclude. "The best research points to the problem only getting worse in both clinical and financial terms. A number of interventions have been successfully implemented, and many are cost-effective, though some are more so than others."