More than two-thirds of Australians living outside major cities are overweight or obese, and extremely obese corpses are creating a safety hazard at mortuaries, according to two studies released Sunday.

Meanwhile, pathologists are calling for new "heavy-duty" autopsy facilities to cope with obese corpses that are difficult to move and dangerously heavy for standard-size trolleys and lifting hoists.

The bodies presented "major logistical problems" and "significant occupational health and safety issues," according to a separate study, which found the number of obese and morbidly obese bodies had doubled in the past 20 years.

In the past year, there have also been requests for larger crematorium furnaces, bigger grave plots as well as super-sized ambulances, wheelchairs and hospital beds.