According to the Heart Foundation analysis, based on Australian Bureau of Statistics data, the Darling Downs, which includes towns such as Dalby and St George, is the most obese part of Australia. More than 44 per cent of its residents are obese, and almost three-quarters do not get enough physical activity to be healthy.

In NSW, the Riverina region, which includes Griffith and Wagga Wagga, has the dubious distinction of the highest proportion of obese residents. There, a third of residents are obese, and 81 per cent do not complete the two and half hours a week of moderate to vigorous physical activity considered necessary for good health.

City of Wagga Wagga mayor Rod Kendall said he was surprised by the finding, and suggested that the convenience of the car and the abundance of free parking in country areas could be a contributing factor.

"If you live in a country town, you park in front of the shop you shop in. Maybe that convenience of access is something that's working against us," he said.

The other worst-performing regions in NSW were Sydney outer west and Blue Mountains (including Penrith), Newcastle and Lake Macquarie, the Central Coast and the far west and Orana (including Broken Hill and Bourke).

At the other end of the scale, the residents of Sydney's eastern suburbs were the most virtuous in the nation. Little more than a quarter of residents of Sydney's east did not get the recommended level of exercise, and less than 14 per cent were obese.

North Sydney and Hornsby, and Sydney's CBD and inner south, including suburbs such as Marrickville, Waterloo and Glebe, also featured in the top ten healthiest regions in the nation.

In Victoria, the town of Shepparton has the dishonour of having the highest proportion of obese residents. There, 36 per cent of residents are obese, and 77 per cent did not complete the two and half hours a week of moderate to vigorous physical activity considered necessary for good health.

Ballarat is not much healthier, with almost a third of its residents classed as obese, while 85 per cent do not get enough exercise.

At the other end of the scale, the residents of inner Melbourne, an area stretching from Elwood to Essendon and from Flemington to Fairfield, was the state's leanest.  Less than 14 per cent of residents of that clump of suburbs are obese, and only 30 per cent  do not get the recommended amount of weekly exercise. Nationally, only Sydney's eastern suburbs have a better record.

Melbourne's inner east, including suburbs such as Kew, Hawthorn, Blackburn and Burwood, was also among the national top ten, with 13 per cent obesity, and one in two people getting the recommended level of weekly exercise.

NSW had the second-lowest proportion of obese residents of any state (26.4 per cent), outdone only by Victoria (25.7 per cent) and the ACT (25.1 per cent).

However NSW bettered Victoria in its proportion of people who get enough exercise. In NSW, 55.1 per cent of people don't get enough exercise, compared to 56.6 per cent of Victorians.

Across Australia, 27.5 per cent of adults are obese, and 57 per cent do not get enough exercise for good health.

Heart Foundation chief executive Mary Barry said the statistics were both alarming and sobering.

"Far from being the fit and active, outdoors type often portrayed, this data shows us that nearly one-third of Australians are obese and more than half are living sedentary lifestyles with little or no physical activity in their day.

"The truth is as a nation our waistlines are increasing while our physical activity time is decreasing.

"We are creating bodies that are breeding grounds for heart disease," Ms Barry said.

Heart disease is the single biggest killer of Australians, claiming 55,000 lives a year, or a death every 12 minutes.

Obesity and inactivity are lifestyle factors that significantly increase the risk of heart disease.

Ms Barry said losing excess weight and being active for 30 minutes a day was enough to add years to a person's life.