Queensland children as young as three are suffering chronic obesity in what experts say is an epidemic.
Doctors have told The Sunday Mail they are treating babies who are so overweight they have difficulty walking and exercising.
Some fat children needed oxygen tanks to help them breathe at night because their airways were blocked.
"We have an obesity epidemic," said Brisbane's Professor Jennifer Batch "We are seeing obese babies as young as three who are the average weight of a 9-or-10-year-old."
The revelations come as Governor-General Michael Jeffery warned last night that the "fat lifestyles" of Australian children had created a diabetes time bomb.
The Governor-General told a Diabetes Australia function in Canberra that unless obese children were prised away from their DVDs and video games, they risked joining more than one million Australians with Type-2 diabetes — an illness scientists link to being overweight.
His call for "trim, fit and healthy" children came after reports that an obese three-year-old girl died of heart failure in Britain this week. The girl, who should have weighed 15kg, was 39kg when she was found dead in bed.
Australian experts say the numbers of obese children is continuing to rise despite massive public education.
Professor Batch, director of endocrinology and diabetes at the Royal Children's Hospital in Brisbane, said she had witnessed a sharp increase in child obesity to the point where an overwhelming number of children were affected.
She said obese babies and children were suffering sleep apnea, stomach problems, knee and hip problems and rashes. They were at risk from diabetes, high cholesterol and cardio-vascular problems.
"We have some cases where kids need support at night from oxygen tanks just to help them sleep," Professor Batch said. "Kids today are less physically active and participating in sedentary activities like playing computer games, using the Internet and watching TV. This problem requires intervention on a number of levels. There is a real lack of knowledge about food content and choices."
"We need to look at portion sizes and reduce their consumption of soft drinks and high amounts of sugar." Some parents gave soft drinks to eight-month-old babies, she said. "There is a whole generation who have grown up unable to cook and prepare meals from scratch. . . we've become a fast-food nation," Professor Batch said.
Poor nutrition, lack of exercise and obesity are now the major causes of disease here, according to Queensland Health.
Australia, the UK and the US are among the three fattest nations. Between 1980 and 2000, obesity in Australian men rose by 80%, while the rate among women rose 2½ times. Experts estimate 25% of children and young people are overweight or obese, taking the number to about 1.5 million.
Major-General Jeffery said exercise and sport were the keys to reducing the diabetes menace which he called "diabesity". Almost 40% of children did not play sport or engage in physical activity.
"Although the consumption of high-fat and sugary foods plays an important role in obesity, it seems to me that it can also be the result of a fat lifestyle," he said. "Clearly we need to act, and prising children away from their DVDs and Play Stations would be a good start."
The Federal Government is preparing a policy to urge children to exercise after school.
In Britain, Dr Sheila McKenzie of the Roya1 London Hospital said she was seeing children literally "choking on their own fat" at her clinic.
A report to the UK House of Commons warned today's children would be "the first generation to die before their parents as a result of obesity".