The Australian Institute of Health & Welfare reports these facts. In 2017/18:

25% of children and adolescents (2 to 17) were overweight or obese
67% of adults were overweight or obese
31% of all Australians were obese – up 12% from 1995

It is estimated that there will be $88 Billion additional costs to the Australian economy in the 10-year period 2015 to 2025, if no action taken to slow the rise of obesity.