SOUTH Australia’s Health Minister John Hill says phone surveys show most consumers want the government to regulate the way junk food is marketed to children.

Fifteen years ago, one-tenth of four-year-old girls and boys in South Australia were overweight or obese, but that figure was now around one in five, Mr Hill said in a statement on Wednesday.

Research showed that between March 2010 and January 2011, the top nine food advertisers in SA were all fast food outlets, which spent $13 million on metropolitan TV advertising, nearly all in children’s viewing time, he said.

“This is over six times the amount of money Quit campaigns used to drive down smoking rates,” Mr Hill said.

He said the key problem was that voluntary self-regulation was restricted to children’s and some general programs, when in reality children watched a much wider range of programs.

Mr Hill wants the food industry to work with the government to take action, including defining a common criteria to decide which foods are healthy and unhealthy.

He also wants them to extend voluntary initiatives to the times of day when large numbers of children actually watch TV, by extending restrictions into evening timeslots.

SA will be working with the Australian National Preventive Health Agency (ANPHA) and the Australian Health Ministers Advisory Council (AHMAC) to host a national seminar next year to discuss action on unhealthy food advertising.