By Miles Godfrey of AAP

The authors of a major new Australian study into childhood obesity are advocating a big increase in the number of juvenile gastric banding operations to tackle the growing prevalence of morbidly overweight kids.

Around ten per cent of Australian boys, and seven per cent of girls, are now obese, Associate Professor John Dixon, head of the Obesity Research Unit at Melbourne's Monash University, says.

This is up from a prevalence of about two per cent in the 1980s.

In other countries the numbers are even greater.

But healthy eating and exercise simply doesn't work for some of the most extremely fat children, the two-year study, published in the Journal of the American Medical Association (JAMA) on Wednesday, found.

It suggests gastric banding - currently a surgical operation almost exclusively only offered to adults - is a much more effective and safe method of weight loss for children aged 14 to 18.

The study took 50 extremely overweight children and gave 25 of them laparoscopic adjustable gastric bands and put the other 25 on healthy eating and exercise plans.

Those with gastric bands lost, on average, 79 per cent of their excess weight while those on the healthy lifestyle program achieved losses of only 13 per cent.

The research was conducted at the Centre for Obesity Research and Education (CORE) at Monash University and the Centre for Adolescent Health at the Royal Children's Hospital, Melbourne.

Head of CORE and lead author of the study, Professor Paul O'Brien, said the gastric band group also showed improvements in general health and self-esteem.

"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," Prof O'Brien said in a statement.

Associate Professor Dixon said healthy lifestyles were still capable of helping obese youngsters achieve weight loss - but he advocated an increase in juvenile gastric banding.

"We should always try and exhaust other options but what this study shows is that there is now no reason why we shouldn't extrapolate down adult treatments - gastric banding - into adolescents," he told AAP on Tuesday.

"We're cautious about giving some surgical treatments to young people; adults are more willing to take risks with operations and experimental treatments etc.

"What we are saying is that there are no extra safety risks with gastric banding among children. And it is every bit as effective."

Prof Susan Sawyer, also a co-author and director of the Centre for Adolescent Health, Royal Children's Hospital, Melbourne, said governments now faced the challenge of ploughing more resources into additional clinical services for obese children.

The authors stressed gastric banding was not a "quick fix" approach and said careful assessment counselling prior to gastric band operations would be required.

© 2010 AAP