Gastric bypass surgery could have life-extending benefits for most of the five percent of Americans who are very obese, a new study suggests.

The study, led by researchers at the University of Cincinnati, concluded that the benefits of this form of weight-loss surgery far outweigh the risks for most people who are morbidly obese, which is defined as having a body mass index of 40 or higher.

But individual decisions on the surgery rely on factors such as age, and a special program to help physicians and obese people balance the benefits and risks of weight-loss surgery is on the way, the researchers said.

"In the future, we plan on having a Web-based decision support tool," said Dr. Daniel P. Schauer, assistant professor of internal medicine at the University of Cincinnati Academic Health Center. "Hopefully, it will be available some time in the next year. It is in the development and testing phase."