Choosing the Knife

"Today" show weatherman Al Roker and singer Carnie Wilson are likely to have a lot more company in the once-exclusive ranks of those who have had weight-loss surgery.

A recent Medicare decision expands coverage for gastric bypass and other weight-loss surgery to people with a body mass index of 35 or greater -- about 60 pounds or more overweight -- who also have at least one weight-related medical problem, such as diabetes, sleep apnea or heart disease.

In 2005, about 170,000 people in the United States had weight-loss surgery, according to the American Society of Bariatric Surgery (ASBS). Medicare paid for 6,000 of those procedures. Ninety percent of those operations were performed on people younger than 66, who are disabled by their weight and other medical problems, according to the federal Centers for Medicare and Medicaid Services (CMS). Since private insurers generally follow Medicare's lead, weight-loss surgery is expected to increase significantly throughout the country.

But experts caution that surgery is not a cure for obesity. "It's a tool designed to help you help yourself, not a free ride," says surgeon Harvey Sugerman, past president of ASBS and professor emeritus at Virginia Commonwealth University.

Some worry that the expanded coverage sends the wrong message, since medical treatment for obesity is limited at best. "Insurance companies won't cover the medical care of obesity treatment, but they're willing to pay for surgical intervention," notes Arthur Frank, director of the George Washington University Weight Management Program. "That's outrageous. It drives people into surgery . . . and may create the wrong incentives."

Here are some of the caveats to keep in mind about gastric bypass and other weight-loss surgery, which has a mortality risk of about 0.5 percent to 2 percent, about the same as a hip or knee replacement.

Surgery only gives a jump start. The procedures promote weight loss in two ways: either by diverting food from the stomach to a lower part of the digestive tract where nutrients can't be absorbed, or by reducing stomach size so that less food can be consumed at a given time. Overeating after surgery can result in vomiting or in "dumping," a condition that lasts about 30 minutes and is characterized by lightheadedness, nausea, flushing and sometimes diarrhea.

"But you can always beat the system by drinking milk shakes or eating ice cream," says Frank, who notes that the same healthy habits prescribed for weight loss -- eating less and moving more -- are still required after surgery.

That may be particularly challenging since people who become morbidly obese usually have difficulty controlling what they eat and often don't exercise. "Lots of people go into this with unrealistic expectations that the surgery will take care of it all and this will be it," says Ronna Saunders, director of the Center for Behavioral Change in Richmond, who counsels people after weight-loss surgery and screens them before it.