While the total number of overweight Aussies has fallen, the proportion of overweight or obese South Australians is above the national average.

According to the latest Medibank Better Health Index, the proportion of overweight South Aussies (64.3 per cent) was second only to QLD (65.2 per cent).

The national average was 62 per cent, based on the country’s mean Body Mass Index score. This number fell to 27.37 in 2017 from 27.44 in 2016.

But Medibank’s Dr Linda Swan said the improved BMI score still represented a “crisis”.

“Although these findings suggest a potential swing in the right direction, it’s important to bear in mind that this data reflects a subtle change over a relatively short period,” she said.

“And while we hope to see this decline become a more pronounced trend, it’s too soon to tell whether it will represent a meaningful change in our national weight over time.

“In the meantime, it’s important all Australians take steps to maintain a healthy lifestyle with regular exercise and a balanced diet to help keep their weight in check.”