Many mothers are failing to take an interest in what their children eat for lunch, research has found.
Many children are aware of the need to eat healthily
The study by market analyst Mintel identified 50% of mothers as 'unperturbed parents' who take little or no interest.
In contrast the research found many children adopt a healthy approach to what they eat.
Seven in ten 11 to 16-year-olds agreed it was important to eat a balanced diet.
Just one in ten seven to 16-year-olds said they found buying health foods a strange concept, while just 22% admitted they found it difficult to resist eating too many sweets.
Popular lunchbox items
Savoury sandwiches and rolls - 62%
Crisps and snacks - 52%
Fresh fruit - 47%
Still fruit drinks - 39%
Sweet biscuits - 30%
Unprocessed cheese - 18%
Cakes - 14%
Chocolate - 13%
Raw vegetables - 10%
Fizzy drinks - 5%
Amanda Lintott, a consumer analyst at Mintel, said that despite the fact that many children were overweight, most seemed to understand the need to health healthily, and not overindulge.
"But recognising the importance of healthy eating is only half the battle, as children now need to be encouraged to put this in to practice.
"The message is still not getting through to all children, and there remains further scope for education."
The research suggested that parents were a significant part of the problem.
Just one in four mothers were identified as 'persisting parents' who aim to give their children the best food they can.
Overall, just two in five mothers (42%) always pack a lunch for their child.
The study also found that young girls take a greater interest in healthy eating than boys.
They are far less likely to try not to eat too many sweets (47% vs 39%), eat a balanced diet (75% vs 67%) and try not to eat too much (56% vs 41%).
However, they are far more likely than boys to diet, comfort eat and experience guilt when eating.
Ms Lintott said: "These results suggest that experts need to tread a fine line when talking about diet with younger girls as any preoccupation with food can be unhealthy.
"Although it is important to encourage healthy eating, it is clear that this can sometimes be taken to the extreme by some girls."
Robert Westhead, of the Food Standards Agency, said: "It's widely know that many children know how to eat healthily, but the problem is translating that knowledge into actually eating more healthily.
"We would encourage parents to help their children pack healthy lunchboxes.
"We provide lots of practical tips on our website about how to make a nutritious and tasty packed lunch.
"Also, the agency is helping schools teach children about how to make healthier choices about what they eat."