The Agency for Healthcare Research and Quality has released a new report entitled, “Pharmacological and Surgical Treatment of Obesity.” The report is available online at http://www.ahrq.gov/clinic/epcsums/obesphsum.htm.

According to the report, surgery may be more effective for weight reduction in extremely obese patients who have tried and failed to lose weight with exercise and diet. Surgery also can improve control of some obesity-related health problems such as high blood pressure and diabetes.

Extremely obese persons (those who have a body mass index [BMI] of 40 or greater) often have severe health problems such as heart disease, musculoskeletal disorders, and sleep apnea that limit daily activities and put their lives at greater risk for adverse events. An online BMI calculator can be found at http://www.nhlbisupport.com/bmi.

Roughly 60 million adults in the United States are obese, and 9 million are extremely obese. A BMI of 40 or greater is not the sole criterion for selecting patients who might benefit from weight-loss surgery. Of the 9 million adults who are extremely obese, only a small fraction (about 1.5 percent or 140,000) undergo weight-loss surgery each year in the United States.

Approximately 20 percent of those who have weight-loss surgery experience minor complications. However, some complications can be serious and include nutritional deficiencies, leaks from staple line breakdown, and deep venous thrombosis. Laparoscopic procedures result in fewer wound complications and incision hernias than traditional abdominal surgery.

Bariatric surgery may be more effective than pharmacologic therapy for people with a BMI of 35 to 40. However, the evidence is not strong enough to draw firm conclusions for this group. Roux-en-Y gastric bypass surgery results in greater weight loss (an average of 20 lb) than does vertical-banded gastroplasty.

There is not enough evidence to draw conclusions about differences in the safety of weight-loss surgery, which include adjustable gastric banding, vertical-banded gastroplasty, and biliopancreatic diversion procedures. Less than 1 percent of patients operated on by experienced bariatric surgeons die as a result of the surgery or from complications, but the rate may be higher for less-experienced surgeons.

Some prescription medicines, particularly orlistat (Xenical) and sibutramine (Meridia), promote moderate weight loss when prescribed along with recommendations for dieting. The amount of weight loss directly attributable to these drugs averages less than 11 lb, but research shows that even such a modest weight loss may decrease the occurrence of diabetes.

No weight-loss drug appears to be superior to others and, like all medications, each has side effects. The drugs have not been studied sufficiently to evaluate the risk for rare side effects, nor has there been enough research to determine the optimal time to treat obesity with drugs or how this may vary by patients’ age, gender, or race.

Very little research has been done on either surgery or medical treatment of obesity in children and adolescents.

In December 2003, the U.S. Preventive Services Task Force recommended that physicians screen all adult patients for obesity, and offer or refer obese patients for intensive counseling and behavioral interventions to promote sustained weight loss.