The obesity rate has ballooned from 11 per cent in 1989 to 28 per cent, with a report showing even the slimmest area of Australia has a weight problem.
More than six out of ten Australian adults are too fat to be healthy, according to data that shows 10.8 million are overweight or obese.
Obesity has ballooned from 11 per cent in 1989 to 28 per cent in 2011-12, when the data for a new National Health Reporting Authority document was recorded.
On a local level, even the slimmest area has a problem, with almost half the population obese or overweight, according to the document released on Thursday.
The fattest area is western NSW, where 79 per cent of people are overweight or obese, according to the report compiled by the authority at the request of the Council of Australian Governments (COAG).
It divides the country according to the Medicare local areas established in 2011 to promote community-level health management.
The second fattest area is Queensland's Townsville-Mackay, followed by country South Australia, Victoria's Gippsland and Western Australia's Goldfields-Midwest.
About three quarters of the population are overweight in all these areas.
The report regards a body mass index of 25 or more as overweight and 30 or more as obese.
Eastern Sydney is the slimmest area, with 49 per cent of people overweight or obese, while Sydney's north shore and beaches and inner northwest Melbourne follow at 50 per cent.
Obesity rates range from the north shore and beaches' 14 per cent to 41 per cent in Lodden-Mallee-Murray, which spans Victoria and NSW.
While overweight or obesity rates increase with geographic remoteness and lower socioeconomic status, 54 per cent of adults in the wealthiest urban areas are overweight or obese and 19 per cent are obese.
In 12 local areas, more than three in ten people are obese, according to the report.
"Rates of adult obesity have been rising very rapidly over time," says performance authority CEO Dr Diane Watson
She hopes the data will help doctors and officials come up with localised solutions.
COAG wants the proportion of the population in the healthy weight range to increase to 42 per cent by 2018.
The figure was 36 per cent in 2011-12.