March 8/Canberra, Australia/Canberra Times -- Young children believe that breakfast cereal is tastier if it comes in a box decorated with popular cartoon characters, new research suggests.

A study by U.S. researchers published in the journal Archives of Pediatrics and Adolescent Medicine has sparked renewed calls for a crackdown on junk food marketing targeted at children.

Researchers at the University of Pennsylvania conducted an experiment with 80 children aged between four and six years.

Children were shown boxes of cereal labelled either "Healthy Bits" or "Sugar Bits."

Some of the boxes included animated characters such as penguins from the movie Happy Feet.

The children who saw a popular media character on the "Sugar Bits" box reported liking the cereal more than those who viewed a box without the character on it.

Those children who were given the cereal labelled "Healthy Bits" reported liking it more than those who ate the same cereal under the name "Sugar Bits."

No significant differences were found among children in the "Healthy Bits" group based on the presence or absence of the characters.

"The results of this experiment provide evidence that the use of popular characters on food products affects children's assessment of taste," the authors wrote.

"Messages encouraging healthy eating may resonate with young children, but the presence of licensed characters on packaging potentially overrides children's assessments of nutritional merit."

Obesity Policy Coalition senior policy adviser Jane Martin said there should be a complete ban on the marketing of unhealthy food to children, including through the use of licensed characters, such as Shrek.

"Our position is that there should be no junk food marketing to children at all, and this particular form of marketing is used to target young children," she said.

Martin said food manufacturers encouraged children to "engage with the brand" by including children's games on their websites that featured animated characters used to market products.

Public Health Association of Australia chief executive Michael Moore said a range of measures were needed to protect children from the marketing of unhealthy foods.

"Restrictions on marketing to children should not only include free to air television advertisements ... it should also include the nexus between sport and junk food and the use of trinkets which are attractive to kids."

Moore said the over-consumption of sugary, salty and fatty foods could cut decades off children's lives.

From the March 21, 2011, Prepared Foods E-dition