Only 1% of children knew about the importance of regular exercise

Only 1% of youngsters were aware that regular exercise and playing sport was vital for staying healthy.

The survey of more than 1,100 secondary school students also showed 58% did not know that eating more fruit and vegetables would improve their diet.

Only 5% knew fish was healthy and only 12% were aware they should try to cut down on salt, said The Grocer survey.

Fat worry

"Exercise is critical. Everyone keeps saying it, but it really needs to be hammered home," said Rosemary Duff, from market researchers Childwise, which conducted the poll on behalf of the trade magazine.

Almost one in three schoolchildren questioned were worried about high levels of fat in their diet, a figure which increased to 53% among 11 and 12-year-olds.

The research casts some doubt on claims that television advertising is contributing to childhood obesity.

Of those questioned, just 1% thought "persuasive advertising" was the overriding factor in their choice of what to eat.

"It is interesting how low the figure for advertising is and I think that kids are genuinely not influenced by it," said Ms Duff.

"It might bring a product to their attention - but if it doesn't taste good, they won't eat it again."