Junk food TV ads more frequent during kids's peak viewing times

Junk food advertisements are shown more frequently on TV at during children's peak viewing times, according to a study.

The research also showed that children were exposed to twice as much unhealthy food advertising as healthy food advertising.

Researchers from University of Adelaide in Australia found that children would view more than 800 junk food ads each year, if they watched 80 minutes of television per day.

By building a TV monitoring system, believed to be the first of its kind in the world, researchers were able to capture an entire year's worth of television and ads from one free-to-air commercial TV network in South Australia.

"This is the most robust data we've seen anywhere. It is the largest dataset ever used by health researchers for examining food advertising in Australia, and probably the world," said Lisa Smithers, associate professor at University of Adelaide.

"Most research in this area is based on only a few days of data, and there are no Australian studies taking seasonality into account," said Smithers, who led the study published in the Journal of Paediatrics and Child Health.

Thirty thousand hours of television containing more than 500 hours of food advertisements - almost 100,000 food ads - were logged during 2016.

Snack foods, crumbed or battered meats, takeaway or fast food and sugary drinks were among the most frequently advertised foods.

During children's peak viewing times, the frequency and duration of "discretionary" (ie junk) food advertising was 2.3 times higher each hour than for healthy foods.

Across the year, discretionary food advertising peaked at 71 per cent of all food advertising in January, dropping to a low of 41 per cent in August.

There is also no process for routine, independent monitoring of children's exposure to food advertising, researchers said.