It is world obesity day tomorrow, and a group of professors from the health policy think tank, the Mitchell Institute at Victoria University have kindly put Australia on the scale.

Right at the bottom of the list is Nedlands an affluent western suburb of Perth, with just 12.8 per cent of its adults weighing in heavy.

The rate of obesity varies dramatically across the country depending on wealth and where people live, and Katherine, with its heat and heavy reliance on cars, is well above the national average.

Katherine has the highest amount of overweight and obese people in Australia, with almost 80 per cent of the adults tipping the scale.

It also has the second highest rate of obesity in Australia with more than 43 per cent of people obese, with almost twice the rate of obesity as found in Darwin.

Professor Rosemary Calder from the Mitchell Institute said it is an issue of environment and socioeconomic factors.

"We know place impacts the rate of overweight and obese people. Areas more remote tend to have more fast food outlets and less options for purchasing fresh fruit and vegetables," she said.

"There is often an over reliance on cars for transport as well."

The proportion of Australian adults with obesity has risen 27 per cent in the last 10 years to almost a third of the population, placing them at a higher risk of diabetes, some cancers, heart disease, arthritis and dementia.

"Places like Melbourne and Sydney have beautiful leafy green parks and lots of public transport, so people are incorporating exercise on their way to work," Professor Calder said.

"People living in metro areas are well serviced by public transport, bike paths... which enables people to be physically active in their commute to work, rather than rely on the car.

"More affluent people people tend to live in these areas as well, and have access to weekend markets where healthy food is dirt cheap.

"They might be able to pay for gym access and sporting groups too."

Professor Calder said policy change was needed at every level government to address the epidemic.

"The establishment of a national preventive health taskforce by the Federal Minister for Health is an essential first step in the right direction," she said.

"It is vitally important that governments at all levels focus on collectively addressing the impact of where we live on our health."

She 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.

"There is opportunity for councils to put in place infrastructure to encourage people to be more active and healthy. "

More broadly, the Professor said there was a need to look at our policies around sugar and salt content in processed foods.

"The UK, for example, has successfully supported significant reductions in the salt content in processed food, a major contributor to poor health, particularly in low socio-economic communities."

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