Research in Australia indicates that the country is on its way to overtaking the United States as the fattest nation in the world.
Obesity among Australian children has doubled in the last 10 years hitting 20% and still growing fast.
This, the report says, is leading to juveniles developing conditions normally only found in adults, like high-blood pressure, heart disease and type two diabetes.
A BBC correspondent in Sydney says the image of Australia as a sporting nation populated by fit, healthy people has been dented by the latest statistics on obesity.
Experts in Australia are warning that unless urgent preventative programmes are taken, Australia will become the fattest nation in the world in as little as a generation.
Doctors now regard obesity as a global health threat, saying it has raised the incidence of heart disease, stroke, breast cancer and colonic cancer.
Another report published by Germany's Federal Statistics office indicates that nearly half of German adults are overweight.
Experts say reducing calories alone is not enoughHigh rates of obesity have been reported among the elderly, men and the widowed.
Studies by a Washington-based Worldwatch Institute show that the number of those overfed and overweight around the world has risen to 1.1 billion.
In the United States 61% of all adults are overweight compared to 54% in Russia, the UK has 51% and Germany 50%.
The report says the financial costs of obesity-related problems in the States is now estimated at $99bn a year.
Worldwatch Institute Chairman Lester Brown says that there is growing evidence that cutting down calories is not enough to combat obesity.
He says regular exercise is needed to maintain healthy body weight.