Remember Tony the Tiger? How about Snap, Crackle and Pop or the Laughing Cow? New research has found that the characters used to advertise foods to us as children could be influencing our food choices as adults.

UK and US researchers set out to investigate the long-term effects of exposure to adverts in childhood.

In four different experiments, they assessed how healthy certain food products were judged to be. Some of these products were heavily advertised when the participants were children. Some only started being advertised when the participants had already reached adulthood.

All of those taking part reported how they felt about the characters used and also how healthy they thought the products were.

The study found that those who were exposed to advertising tended to feel positively towards any advertising character that was used. They were also much more likely to rate the nutritional value of the brand more favourably, even though it was years later.

The researchers also found that these effects were not just limited to the products originally advertised. When they invented fictitious new brand extensions associated with a known advertising character, people tended to rate these made-up products as healthier.

"People should check the labels on the products they've loved since childhood. It's possible that affectionate feelings for brand characters mean they are overlooking relevant nutritional information. Also, many advertising characters have been around for decades. Parents should be mindful that their judgment of products associated with ads they saw as children themselves, might be clouded," warned lead researcher, Dr Paul Connell, of City University London.

Overall, the study found that if children were exposed to advertising before the age of 13, they tended to be biased towards the products that were supported by ads. For example, French fries and sweetened cereals tended to be rated healthier if people were exposed to ads for them when they were children.

Dr Connell noted that children first see ads as entertaining and even when they can tell the difference between them and actual programmes, they are still less critical than adults because they do not fully understand the power of persuasion.

"We suggest that parents discuss the persuasive nature of advertising with their children, and encourage them to develop critical thinking skills in response to advertising messages. They may wish to point out that commercials use funny stories and exciting characters to entertain the viewer, but that commercials may not provide all the important information about the product," he said.

He added that for very young children, parents should consider limiting the amount of advertising they see ‘until the children are old enough to have these conversations'.

Details of these findings are due to be published in the Journal of Consumer Research.