On top of that, more than 21.9 per cent of children, aged two to 17, are also considered as overweight or obese in the local government area.

And, both children and adult males are more likely than females to tip the scales, according to the latest data from the Australian Bureau of Statistics, Australian Health Survey.

A group of professors from the health policy think tank, the Mitchell Institute at Victoria University, put Australia on the scale for World Obesity Day on Friday, October 11.

Right at the top of the list in New South Wales is Forbes, with 77 per cent of its adults weighing in as overweight or obese.

At the bottom of the list are the affluent suburbs of Willoughby and North Sydney, with 49.9 per cent of their adults weighing in heavy.

It all comes down to where you live and how much you earn, according to the Mitchell University's professors, with people in regional areas (42 per cent) three times more likely to be overweight than those in wealthy inner Sydney (14 per cent).

Professor Rosemary Calder of Mitchell University said it was no surprise that Sydney's wealthy suburbs have the lowest rates of obesity.

"These suburbs are usually green and leafy, with more space dedicated to parks, gardens and recreational facilities," she said.

"They often are well serviced by public transport, bike paths and are relatively close to where people work, which enables people to be physically active in their commute to work, rather than rely on the car.

"They have a greater density of shops selling fresh fruit and veg, greater competition promoting lower prices for healthy foods and fewer fast food outlets," Professor Calder said.

Two-thirds of Australians are now overweight or obese, placing them at higher risk of diabetes, some cancers, heart disease, arthritis and dementia, according to Mitchell University.

Professor Calder said action was needed to focus prevention strategies in the most disadvantaged communities.

"We have spent too long as a nation expecting individuals to be able to change their behaviour to reduce their weight," Professor Calder said.

"However, the evidence is very clear that this has little chance of success without a very strong focus on the environmental factors in the places where we live that contribute to poor nutrition and inactivity."

Professor Calder said policy change was needed at every level of government.

"The establishment of a national preventive health taskforce by the federal minister for health is an essential first step in the right direction. It is vitally important that governments at all levels focus on collectively addressing the impact of where we live on our health," she said.

Professor Calder said places with the highest rates of obesity, also have much higher rates of smoking, inactivity and chronic illness and are largely low-socioeconomic communities, highlighting the impact of poverty on health.

"Local governments are critical to local planning and the creation of healthy and active spaces for their residents. However, they are often hampered by lack of funding and regulatory power," she said.