loss surgery have actually had the procedure; in 2002, for example, only 0.6 percent of an estimated 11.5 million morbidly obese patients underwent weight-loss surgery. Meanwhile, in-hospital death rates among weight-loss surgery patients as a whole fell by 64 percent-from 0.89 percent to 0.32 percent between 1998 and 2002. In spite of the overall decline, the death rate for men, which dropped from 2.76 percent to 0.79 percent, was still three times higher than the 0.24 death rate for women.

"This study clearly shows another side of the challenge that America's obesity epidemic poses to the nation's health care system. In the absence of more effective means of preventing obesity, the demand for surgery and its costs will continue to increase," said AHRQ Director Carolyn M. Clancy, M.D. "These findings provide valuable national estimates for the present and future for Medicare, Medicaid and private health plans."

The authors further suggest that future use and costs of prescription weight-loss drugs also could increase significantly. While 63 million Americans were medically eligible for weight-loss drugs in 2002, less than 2.4 percent were prescribed them. The average spending on weight-loss drugs that year was $304 per patient, with health plans paying roughly three-fourths of the expense and patients paying the balance.

According to lead study author William E. Encinosa, Ph.D., newer, more effective drugs now under development to block cravings or appetite will likely increase the demand for prescription weight-loss medications.