New research confirms Australian children are being bombarded with hundreds of TV ads promoting unhealthy foods.

This "conservative" estimate equates to approximately five hours of continuous viewing, according to the research released by the National Heart Foundation on Tuesday.

Researchers at the University of Adelaide worked with telecommunications engineers to design a bespoke TV monitoring system to capture the number of ads shown on one TV network (which took in four channels) over an entire year.

In total, more than 100,000 food ads were logged over the 30,000 hours of television monitored in 2016.

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

More than twice as many ads promoting these unhealthy foods compared to ads advertising healthy foods were shown during children's peak viewing times, according to the analysis.

"The times when most children are watching television are also the times when there's the most unhealthy foods advertising," said lead researcher Professor Lisa Smithers.

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.

Prof Smithers says the research confirms Australian children are getting "quite a lot of exposure" to junk food advertising.

"On average Australian data suggests that children aged five to eight years watch about 80 minutes of TV per day," she said.

"Using the 24 hour clock our conservative estimate says that children will probably be exposed to over 800 advertisements for unhealthy foods - which is about four hours of continuous content."

But the figure is likely to be higher, she added.

"If we actually look at the time when most children are watching TV, like over 200,000 children in the audience, it actually works out a little bit more. It's more like a thousand ads watched and over five hours of total duration of unhealthy food advertising, so that's quite a lot of exposure," Prof Smithers said.

"Another issue to remember is that this is just television, children are being exposed to advertising from other media as well," she said.

National Heart Foundation CEO Adjunct Professor John G Kelly described the research findings as "disturbing".

It's now hoped more will be done to protect children from the effects of junk food advertising.

"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," said Prof Smithers.

"Australian health, nutrition and policy experts agree that reducing children's exposure to junk food ads is an important part of tackling obesity and there is broad public support for stronger regulation of advertising to protect children," she said.

The study is published in the Journal of Paediatrics and Child Health.