The British Heart Foundation (BHF)'s survey also revealed that nearly one in ten of the 1,000 children questioned thought chips were mostly made of oil, while others suggested eggs, flour, and even apples.
"It sends a shiver down my spine to discover that so many children don't even know what chips are made of," said BHF director general Peter Hollins.
"Kids have lost touch with even the most basic foods and no longer understand what they are eating. Banning foods or telling children not to eat them is not enough - we must engage children in understanding why certain foods are less healthy than others, and encourage them to become interested in what's on their plate."
In terms of market value, children's products contribute about €14-15bn to the overall €700bn food and drink market in Europe. But with a further 440,000 UK children predicted to become overweight or obese in the next two years and a quarter predicted to be obese by 2020, poor nutrition among children is clearly a critical issue needing urgent attention.
As a result, the BHF has launched this week a major new campaign, Food4Thought, to get children - in particular 11 and 12 year olds - thinking about what is in their food and how they can make heart healthier choices. On billboards nationwide are posters showing the common ingredients of cheeseburgers, hot dogs and chicken nuggets. The images of gristle, bones and connective tissue are obscured using a 'censored' stamp.
"This campaign is about talking to children in their language and sparking their curiosity so that they think about what they eat and start demanding healthier options," said Hollins.
The BHF is also pushing for the marketing of unhealthy food and drink products to children to be banned, for nutritious food to be affordable and for children to have the opportunity to learn practical cooking skills.
"There is no single solution to improving children's diets, but we must address the problem urgently in a coordinated way," said Hollins. "If we do not, I fear many of today's children will die prematurely from heart disease as a result of society's hesitation or reluctance to act."
The BHF campaign microsite, contains uncensored contents of the adverts to enable consumers to find out more about what's on their plate.
There is increasing pressure on food makers in Europe to meet new nutritional demands. The UK government recently announced plans to ban junk food in the nation's schools, bringing an end to the sale of crisps, chocolate and fizzy drinks in school vending machines while earlier this year, France banned all vending machines in schools across the nation.
France's food standards body, AFSSA, supported the ban as part of wider measures. It said in a statement that it was in favour of banning vending machines to discourage snacking, yet more action was needed to improve the nutritional value of school meals.
The UK's Food and Drink Federation (FDF) believes that the food industry is responding to these challenges. "UK manufacturers are committed to providing their customers with both the products and the information they need to help them make the right choices," said FDF president Gavin Neath recently.
"The industry has delivered a huge expansion of choice through innovation and new approaches to marketing and information for consumers. We should not under-estimate the effort and resource that has gone into these changes."