First link has Australia, the country, at 32% obesity Vs. USofA at %41.6.

My only observations, having travelled in both, is that Australia like eveywhere has gotten more urban in past 20 years and I've got a feeling the percentage of Australians significantly past the technical bar of "obese" is very low compared to rates in the US of "well past" "just merely obese".

I'm not sure anyone's broken down the obesity quintile demographics.