MELBOURNE (AFP) - Australian researchers Wednesday said a new study supported the use of lap-band surgery for severely overweight teenagers after it found the procedure helped them lose 80 percent of their excess fat.

The study, conducted at Monash University and the Royal Children's Hospital in Melbourne, showed dramatically better results among adolescents who had the surgery, compared with those on a strict diet and exercise regime.

It found that after two years, teens who underwent the appetite-reducing procedure lost an average of 79 percent of their excess weight, while those who stuck to the rigorous lifestyle shed just 13 percent.

"While this study confirms that some adolescents can achieve substantial weight loss and health improvements through diet and exercise, gastric banding should be considered for those severely obese adolescents who find primary weight loss methods unsuccessful," study author Professor Paul O'Brien said.

The government-funded research, published in the Journal of the American Medical Association, tracked 50 severely obese teens aged 14 to 18 over two years between May 2005 and September 2008.

Half of the groups were given the gastric banding surgery, involving a silicon clamp that shrinks the stomach and reduces appetite, and ordered to eat only three small meals and exercise for 30 minutes each day.

The other 25 were kept on a strictly supervised diet and exercise regime.

The adolescents given the surgery were found to lose, on average, more than 10 times the weight of the other group -- 35 kilograms (77 pounds) each, compared to three kilograms.

In addition, six participants in the lifestyle group withdrew from the study after gaining weight, despite having access to a personal trainer, physician, dietician and regular guidance.

Study co-author Professor Susan Sawyer told AFP that while Lap Band Surgery was not a quick-fix solution, it should be more readily considered for adolescents.

"The results of the study will challenge those who feel uncomfortable about any possible role of surgery for severely obese adolescents," said Sawyer, director of the hospital's Centre for Adolescent Health.

"Until we can find more successful behavioral and medical approaches to treat those with severe obesity, the results of the study unequivocally favour lap-banding in terms of weight loss and therefore are really suggesting that it needs to at least be considered."