At 11 years old, a boy has weighed in at 135kg. But he can't have life-changing surgery.

There are fresh calls to help children battling obesity after an 11-year-old boy – who weighed about 135kg – was unable to have weight-loss surgery unlike his 15-year-old brother.

The boy refused to go to school because the playground became too difficult for him psychologically.

“It was not worth it, the boy could learn nothing in the environment that had been created,” said surgeon Dr George Hopkins at the Australian New Zealand College of Anaesthetist’s Annual Scientific Meeting (ASM) in Brisbane.

“It was literally gut-wrenching.”

The Brisbane-based surgeon has been performing effective sleeve gastrectomies on adolescents for years and says his patients have been getting younger.

“The need out there is just screaming, it’s just a question of getting everybody on board,” he said.

"These parents are often desperate. If someone is dragging their kid along to see me because they care, they're prepared to go through all the steps to do it. It's not child abuse, it's anything but."

Childhood obesity may have dropped out of the headlines in recent times, but that doesn't mean the problem has gone away. In fact, it's the opposite. One in four Australian children aged 2-17 are either overweight or obese.

Dr Hopkins says parents of obese children are pleading for the surgical intervention yet the Australian hospital system is "unequipped" to meet their needs.

The surgeon urged his colleagues to start a conversation on the controversial issue.

The current Australian guidelines advise a minimum age of 15 with exceptional circumstances at 14 years old.

Professor John Dixon, head of clinical obesity research at Baker IDI Heart and Diabetes Institute in Melbourne, says Australia has a "major problem" with delivering bariatric surgery to the whole population.

"It's not just children that are in trouble," he told Mamamia.

"Until we see it as an acceptable urgent treatment in adults how on Earth are we going to expect this to be delivered to prepubertal children?" he added.

Professor Dixon says the evidence for bariatric surgery in adults and teens save lives and is cost effective.

"We need bariatric surgery for adolescents and we do need it in very rare cases [for children], like the 11-year-old boy, but we can't even deliver to half our adult population who are absolutely going to die soon if they're not having treatment," he said.

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The "judgement" disease

The professor says very few groups around the world operate on children under the age of 13 or 14-years-old but he says  "it's not an area we should run away from".

"We're not treating obesity seriously as a nation," he said.

"We're pretending that these children don't have a severe disease and there's some sort of lifestyle or issue. Nothing could be further from the truth.

"Until we change our perception of what drives obesity and what drives all the complications of obesity as a nation we won't get around to treating it properly."

Professor Dixon says the epidemic is increasing around the world.

"We don't know how to solve this epidemic, we and many other countries need to put a lot of time and effort as a society into looking at the real determinants," he said.

He says the public's view of the disease is one of judgement.

"We've got to stop blaming the patient, the poor patient is really, really struggling and it's not their fault.

"People can't lose weight... for the vast majority diet and exercise don't do anything."

- With AAP