A morbidly obese two-year-old has become the youngest person in the world to undergo bariatric surgery.

The parents of the toddler from Saudi Arabia who weighed 72 lbs and had a Body Mass Index of 41 sought help because he suffered sleep apnea that caused him to stop breathing while asleep.

Two attempts to control his weight by dieting failed said the medics who carried out the bariatric surgery Mohammed Al Mohaidlya, Ahmed Sulimana and Horia Malawib in an article in the International Journal of Surgery Case Reports.

When he first presented to an endocrinologist at 14 months, the toddler weighed 46 lbs but after dieting for four months his weight increased by 17 pounds.

The doctors from Prince Sultan Military Medical City at Riyadh were unable to ascertain whether the child’s parents stuck to the diet.

By the time the boy was referred to the obesity clinic he weighed 54 lbs and his obesity had led to sleep apnea and bowing of the legs.

A further attempt at dieting failed and when he reached 72 lbs doctors decided to perform surgery.

Surgeons carried out a laparoscopic sleeve gastrectomy on the boy which involved removing the outer margin of the stomach to restrict food intake, leaving a sleeve of stomach, roughly the size and shape of a banana.

Unlike a lap band, the surgery is not reversible.

“To our knowledge LSG has never been tried in very young age children,” the surgeons say in their report. “We present here probably the first case report of the successful management of a two year old morbidly obese boy.”

Within two months the boy lost 15 per cent of his body weight and two years after the 2010 surgery his weight had fallen from 72 lbs to 52 lbs and his BMI of 24 was within the normal range.

Obesity expert adjunct professor Paul Zimmett from the Baker IDI Heart and Diabetes Institute said the case was “shocking” and “very unusual”.

“It’s rather like the other day when we saw one of our spacecrafts going out of our solar system into the dark regions of space, it’s going into unknown territory,” he said of the case.

“We have no idea what effect this may have on the child’s growth and unless he has proper follow up he may suffer vitamin deficiencies.”

In Australia bariatric surgery is not recommended in children aged under 14.

Professor Zimmet said there was definitely a place for the surgery in older age groups.

“There is a lot of evidence now it is almost a better treatment for type 2 diabetes than some drugs,” he said. “We should not let this episode prejudice our views on bariatric surgery.”

In a separate case, Indian doctors are reporting that they performed bariatric surgery on a four-year-old boy.

The child, who weighed 98 lbs, was consuming 1,400 calories a day as a result of a rare genetic disorder – Prader Willi Syndrome – that made him hungry.

This story originally appeared on News.com.au.