The poll revealed that 88% of people say parents should be most responsible, followed by schools. Food manufacturers and broadcasters were in third and fourth place.
The research was carried out by the Food Standards Agency as part of a debate to be held tonight called "Defusing the diet timebomb". While it stops short of asking for an outright ban on advertising food to children, the poll of 2,000 adults revealed that 85% think there should be greater controls over the way fast foods are promoted to children.
The survey also found that 82% of people thought that endorsements from celebrities had considerable influence on children's choice of foods, and that 56% thought that sweets and chocolates should be removed from supermarket checkouts.
Sir John Krebs, chair of the Food Standards Agency, said: "The British public recognise the role that parents must play in improving the diets and health of their children. But it is also clear from our poll that they can't do it on their own -- they need support from schools, industry, broadcasters and government if they are to make a difference."
The findings come a day after Coca-Cola revealed it would no longer be advertising on vending machines in UK secondary schools.
Tonight's debate will include a panel of interested parties including: Andrew Brown, director-general of the Advertising Association; Dr Susan Jebb, head of nutrition and health research at the Medical Research Council; and the celebrity chef Antony Worrall Thompson.
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