A type of weight-loss operation not approved for patients under 18 is becoming more common among obese teens, a fresh study shows. The controversial procedure -- called gastric banding, bariatric surgery or lap banding -- places a silicone loop around the top of the stomach. The rate of gastric banding rose five-fold from 2005 to 2007 among California teens, says the September report in a medical journal called Pediatrics. Most young patients are girls.

Many health experts are alarmed by a rise in gastric banding among all ages. Placing a rigid ring around a moving organ could erode the area over time, critics say. But it's seen as a last-chance choice by some severely heavy people after years of failed diets. Slimmed-down celebrities who've had the operation include Star Jones, Al Roker and Sharon Osbourne. Performing the procedure on adolescents is not forbidden, although the federal Food and Drug Administration hasn't approved it for minors. That means insurance plans typically don't reimburse its cost for teens.

A more traditional operation, gastric bypass, divides the stomach into an upper and lower pouch. That remains the "gold standard" of weight-loss surgery, according to Los Angeles researchers at the University of California who studied records of 590 teens after all types of weight-loss surgery. They urge more studies on the proedures' effectiveness and safety for adolescents, and echo others who worry about possible long-term harm from lap banding.

Surgeon says: "Why do we feel it is necessary to operate on a bunch of 15-year-olds? The theory is . . . that early intervention will result in a substantial difference in the outcomes regarding obesity-related diseases." -- Dr. Marc P. Michalsky, Nationwide Children's Hospital in Columbus, Ohio

Critic says: "There's a fundamental problem with putting a rigid plastic object around a moving organ. You're asking it to stay in place and not erode over a long period." -- Dr. Mary Brandt, director of pediatric surgery, Texas Children's Hospital in Houston

Blogger says: "If you're younger than 18, your support system is probably stronger than it will ever be. So, between family, friends, school, and your doctor there has to be a better, safer why to lose weight." -- Gerry Pugliese at diet-blog.com