A study from the Australian Catholic University's Institute for Health and Ageing has found a person's city address is linked to their obesity level.

The waistlines of people living in Adelaide's outer suburbs increased twice that of their inner city neighbours over four years.

Those living in areas 20km or further from the city centre experienced on average a 2.4cm increase in waist circumference over four years, compared to 1.2cm for those living 9km or less from the CBD.

The findings prompted the institute to call for governments to collaborate with health experts on planning and transport as cities expand.

Study leader Professor Takemi Sugiyama said the reliance on cars in outer suburbs might affect the weight of its residents.

"There is a significant health impact from living in the outer suburbs," he said.

"The finding is alarming as waist circumference, a measure of abdominal fat, is a good indicator of increased risk of chronic diseases, such as diabetes, heart disease and some cancers, and our daily lifestyles play an important role in reducing the risk of these diseases."

While the study used data from 2000 people living in Adelaide, the findings might apply to Canberra because of the cities' similar layout and reliance on cars for transport, Professor Sugiyama said.

Adelaide's outer suburbs were also home to suburban shopping centres with fast food outlets, which might affect the diets of residents, he said.

The study adjusted its results for socio-economic status, another factor linked to weight.

Professor Sugiyama said the findings showed the need for more collaboration between the health, planning and transport sectors to address the health problems related to urban sprawl.

"Expanding the urban growth boundary without providing infrastructure supporting active lifestyles such as public transport, local shops, and open spaces can pose a serious threat to public health over the medium-to-long term."