Aussie health advocates are pushing for a "fat tax" in the country modeled after Denmark's, the first "saturated fat tax" in the world.

Jane Martin, senior adviser for the advocacy group Obesity Policy Coalition, said a fat tax could help curb the rising obesity rate in Australia. Six in 10 adults and one in four children are overweight in Australia.

"We think unhealthy foods should be taxed and the funds raised used to subsidize healthy food for people on a low income," Martin said in a News Limited report.

"We know price plays a role in our decisions, and taxes are used in alcohol and tobacco sales to change people's behaviors."

Denmark became the first country in the world to impose a tax on such foods like butter, milk and processed meats. Under the new law, fatty foods are now subject to a tax if they contain more than 2.3 per cent saturated fats. Consumers will now have to pay an additional 16 kroner ($2.87) per kilo if they want to enjoy their saturated fats.

The National Preventative Health Taskforce has already recommended a tax on junk food in Australia but the proposed tax measure has failed to garner much government support. Taxing junk food wasn't on this week's tax forum in Canberra.

"It's been avoided, really ... pushed sideways, and it's a concern because other countries are looking at this," Martin said.

"It would be interesting to see the impact the fat tax would have in Denmark."

A spokesman for Health Minister Nicola Roxon said the government was doing all it can to tackle the obesity problem in the country.