Boyd Swinburn, professor of population nutrition and global health at the University of Auckland and director of the World Health Organisation Collaborating Centre for Obesity Prevention, addressed a health forum in Canberra on Tuesday to report on the progress of Australia's fight against obesity.

His report is mixed, with Australian adults among the most overweight in the world and the country's children sitting below the OECD average for obesity. But, he says, the number is still trending upward and a plateau at this point would be too high.

"There is no single country that has managed to turn this around," he said.

He added that much of the current focus in prevention was rightly focused on children, but warned that it was going to be a "long time before that generation of skinnier kids comes through the system".

Australia also needed more, compulsory, data collection on the weight of its children through school, he said.

Professor Swinburn used his presentation to call for leadership from "brave" governments who would act to prevent obesity through key measures such as restrictions on junk food marketing to children, fiscal policies such as a tax on sugar, health labelling systems and healthy food policies in any place where the government had jurisdiction, such as public schools and hospitals.

The fifth element to ensure the prevention of obesity was a consideration in all government departments such as agriculture, urban planning, transport and education, Professor Swinburn said.

In defending the idea of such an approach as "nanny-stateism", Professor Swinburn said there were a range of situations in which government dictated behaviour, such as in the car. "Nannies are actually good for children. Nannies look after children, they care for children and they support parents. Big corporations, don't care about them, their job is to stay within the law and make money, period," he said.

He said that the response of the food industry to the obesity epidemic had been "stereotypic" – and identical to that of the tobacco industry before them.

"First they'll deny it, and then they'll fight it, and then they'll obscure it, and then they'll buy the scientists and get the evidence, and then they'll put up front groups to pretend there's a community movement against it, and they'll lobby politicians. It's a standard set of tactics that the tobacco industry does, [and] we've just analysed it with the food industry. They're doing it exactly the same, in fact they're doing it better," he said.

While it was clear what governments needed to do to stop the spread of obesity, Professor Swinburn said what the public could do – with polls already showing the majority of people supporting the restriction of junk food marketing and a tax on sugar – was be more vocal about their support for obesity prevention measures.

He also said the ACT was in an "excellent position" to lead on obesity prevention: its relative small size, education of its citizens and government gave it "lots of opportunities to make this a serious legacy".