Obesity is costing WA public hospitals more than $240 million a year and the costs are predicted to soar to close to half a billion dollars by 2021, the first report of its kind has warned.
A WA Health Department analysis - the first to look at the State cost of acute hospital care for weight-related illness - links high body mass to 18 medical conditions, such as heart failure, which are increasingly being treated in emergency departments and wards.
The most expensive admissions linked to obese patients are for osteoarthritis, heart disease and type 2 diabetes.
Based on more than 62,000 patients treated in 2011, health officials said obesity was costing more than $240 million a year to treat - or 5.4 per cent of total hospital costs.
But they warned the cost was expected to more than double by 2021 unless urgent action was taken to turn the tide around in WA, where two-thirds of adults are believed to be obese or overweight.
The rise over the decade is expected to be fuelled by a massive increase in obesity-caused kidney treatment, with fat-related dialysis expected to cost hospitals $140 million in 2021, up from $28 million in 2011.
Men will continue to account for 50 per cent more of obesity- related hospital expenses than women, with those aged in their 60s the most costly because of their high rate of weight-related osteoarthritis.
Ben Scalley from the department's epidemiology branch, which did the study, said the results showed worrying trends.
"Our findings highlight the urgent need to develop policies and programs that address excess body mass in the West Australian community," Dr Scalley said.
"If current trends continue we can expect the costs of 2011 to have more than doubled by 2021, with projections predicting costs of $488.4 million in constant price dollars.
Dr Scalley warned that the study's cost estimations were conservative and it was likely that the real costs of extra body mass-associated harms were far higher.