April 17 (UPI) -- Children are exposed to twice as much unhealthy-food advertising as healthy-food ads on TV, according to a study conducted in Australia.
The researchers also found ads for junk foods were more prevalent when children were watching television compared with other broadcast times. The research by the University of Adelaide was published Tuesday in the Journal of Pediatrics and Child Health and was sponsored by the Heart Foundation.
They examined one year's worth of television and ads from one free-to-air commercial TV network in South Australia in 2016. That amounted to 30,000 hours of television containing more than 500 hours of food advertisements -- 100,000 food ads. The most frequently advertised items were snack foods, crumbed/battered meats, takeaway/fast food and sugary drinks.
They found children would view more than 800 junk food ads each year if they watched 80 minutes of television per day.
"This is the most robust data we've seen anywhere," Dr. Lisa Smithers, an associated professor at Adelaide said in a press release. "It is the largest dataset ever used by health researchers for examining food advertising in Australia, and probably the world. Most research in this area is based on only a few days of data, and there are no Australian studies taking seasonality into account."
The researchers found that junk-food advertising was 2.3 times more common each hour than for healthy foods during children's peak viewing times.
The advertising varied during the times of year -- 71 percent of all food advertising in January during the summer holiday when children in Australia are out of school compared with 41 percent of all food advertising in August.
In the United States, food advertising accounts for nearly half of all commercial messages on children's programs, according to the National Institutes of Health. An average hour includes 11 food ads that account for 4 minutes and 25 seconds of total ad time.
The Children's Food and Beverage Advertising Initiative is a voluntary, Better Business Bureau-administered self-regulation program with strong standards for food advertising to children. They included requiring participants to advertise to children under age 12 only foods that meet the initiative's uniform nutrition criteria on media.
Companies include McDonald's, Burger King, Coca-Cola, Kellogg, Post, Nestle, Unilever, Hershey, Campbell's, KraftHeinz, Mars, General Mills.
In Australia, advertising during children's TV programs is covered by the Children's Television Standards.
"Diet-related problems are the leading cause of disease in Australia, and the World Health Organization has concluded that food marketing influences the types of foods that children prefer to eat, ask their parents for, and ultimately consume," Smithers said.
She added: "I would love to see the results of our research play a role in protecting children from the effects of junk food advertising."
Norway bans junk-food advertising and France requires healthy eating messages when unhealthy foods are advertised, according to the researchers.