The study by the Obesity Policy Coalition has found some 52 per cent of 186 products sporting such characters on packaging would be deemed "unhealthy" under the Food Standards Australia New Zealand nutrient profiling scoring criterion.

It comes amid wider concerns that some food companies may be selectively using the national food health star rating system and as health authorities around the country work to reduce growing rates of obesity in children.

The Coalition is a partnership between Cancer Council Victoria, Deakin University's Global Obesity Centre and Diabetes Victoria aiming to improve the quality of foods sold in Australia.

Researchers surveyed some 186 products sporting such images on their packaging, a hallmark of marketing to children, between February and April this year, revealing a huge 87 per cent of "snack bars" were unhealthy under the FSANZ criteria.

Other products that would be deemed "unhealthy" included 88 per cent of kids' ice creams and icy poles; 61 per cent of "cheese snacks"; 32 per cent of children's breakfast cereals and 19 per cent of children's dairy snacks.

The survey found two of the most unhealthy products using cartoons to market to children included Kellogg's Frosties, with 41 per cent sugar contact and Kraft's Cheestik Sticks, with 17.5gm of fat for every 100gm.

Coalition executive manager Jane Martin said it was shocking to see so many manufacturers targeting children with unhealthy food, when 27 per cent of children were overweight or obese.

She said such cartoons were being used to "lure children and create pester power" to push parents into buying unhealthy products.

"Children are naturally drawn to fun, colourful characters on foods in the supermarket, and food companies are fully aware of this," she said.

"It's a shame that this powerful marketing tactic is not being used to sell more healthy products instead."