Schools should teach children about fatty foods as part of the national curriculum, doctors have said.
Nutritional education should be a mandatory part of children's schooling to help them make informed decisions about what they eat, they said.
The British Medical Association annual conference in Bournemouth heard that a third of children are overweight or obese.
Dr Louise Harding said: "The UK has a weight problem. It is big and it is getting bigger.
"Overweight children have a tendency to continue gaining weight and become the obese and morbidly obese adults of the future, damaging their health.
"We need to start teaching our children about their food, where it comes from and what's in it.
"How can they make healthy choices if they just don't have the information?
"This is so important it needs to be on our national curriculum.
"If we don't, we are letting down the next generation."