Children who want to make a name for themselves in sport must bin junk food from as early as eight years of age, says the Scottish Institute of Sport (SIS).
A total of 190 athletes receive support from the institute and no stone is left unturned in ensuring that talent reaches its potential. Irene Rioch, a dietician attached to the institute, believes it is never too young for athletes to look at what they eat as fuel for competition.
"When you look at football academies in England, they are taking on children at the age of seven or eight and therefore I think you have to deal with diet at that age," she says. "A lot of that is to get them into the habit of eating well at an early age so that they don't get mixed up in junk food.
"I think a lot more can be done in schools to show the link between healthy eating and top athletes. If children see that their favourite footballer eats healthily, they are more likely to follow that example.
"In the younger children who are serious about sport, we would like to see them eating five pieces of fruit and veg a day. From the age of about 16 we would recommend eight pieces a day."
Liz Mendl, the institute's athlete services manager, concedes that Scotland's diet is not the best but believes the message is getting through. "When athletes come to the Sports Institute, many have been through the area institutes and already have a good knowledge of diet and nutrition," she says.
"Many are pretty knowledgeable and can quote papers they have read on the internet and that is encouraging. It's one thing for athletes to have a good diet when they are at home with their mother's cooking, but we also have to look at when they are away from home competing.
"If they are snacking between matches, then it is important that they do so correctly on the likes of Jaffa cakes and fruit and they continue to eat healthily and take their required pieces of fruit or vegetables a day.
"Cereal bars are now being advertised as a healthy alternative to chocolate but you have to check the fat and sugar content."
She adds: "It is important that the schools offer children the right foods and don't just go for the slot machines that sell cola and crisps."
WATCH WHAT YOU DRINK
Diet is a key component in the development of an athlete and energy drinks are heavily advertised. "But a lot of the commercial sports drinks are loaded with sugar and that goes straight to the teeth," warns Irene Rioch.
"Sports drinks have their place as it is important to keep children hydrated," she says. "A good alternative would be to take one-third fruit juice and two-thirds water as this would give the right levels of hydration, energy and vitamin C."
Chocolate and caffeine are not recommended and athletes are advised to eat more fruit and vegetables.
But food giants such as McDonalds, Cadbury and Coca-Cola do invest heavily in youth and school sport. "It would be better if the likes of a banana company sponsored children's sport but then these companies do not have the same money," Ms Rioch says.