To describe prevalence and trends for overweight and obesity in Australia and to critique the quality of available data on this public health priority.

Comparison of aggregate prevalence data on adult and childhood overweight and obesity in publicly available national or state-based cross sectional surveys and survey series.

All representative population surveys, conducted since 1995, with measured height and weight at a national or state level.

The most recent measured data found that 63.4% of Australian adults and 27.6% of children were overweight or obese in 2014/15. Tasmania had the highest observed adult prevalence of obesity (32.3%) and of overweight and obesity combined (67.5%). The Australian Capital Territory had the lowest observed prevalence of obesity (23.9%) and of overweight and obesity combined (63.0%).

Between 2007/08 and 2014/15, the age-standardised prevalence of adulthood overweight and obesity combined increased from 64.4% to 66.4%. Across states/territories the observed change varied from −5.3% (Western Australia) to 6.0% (Queensland). Amongst children the observed prevalence of overweight and obesity combined increased from 24.7% to 27.6%. Across states/territories the observed change varied from −1.4% (South Australia) to 11.1% (Tasmania).

In Australia, 1 in 10 more adults are obese today compared to 1995. Limitations in the available data mean it is difficult to conclude on trends over time in children, Indigenous Australians, or by state/territory. We need to ensure the continuation and expansion of our National Health Survey and/or explore novel monitoring options from other countries.