Children who eat at fast food chains can consume nearly half their recommended daily calories in one sitting, research suggested today.

Youngsters who went to KFC ate two-thirds of their guideline maximum daily salt intake in one meal, and 11 to 14-year-olds had half the recommended amount of sugar at McDonald's and Burger King.

Consumer magazine Which? polled 1,003 youngsters aged eight to 15 in April about their eating habits at the three chain restaurants.

For some time, healthier options have been available at the outlets, but a third of 12 to 15-year-olds said they chose adult-sized fried foods instead.

Which? said a lack of nutritional information at the branches meant they could be scoffing unhealthy food in ignorance.

So far one branch of Burger King has taken part in a Government pilot to display nutritional data.

The magazine also said that film and toy promotions at Burger King and McDonald's encouraged children to come back.

Four in 10 children aged eight to 11 said McDonald’s was their favourite chain because of the toys and Happy Meals.

Which? Editor Martyn Hocking said: “It's really positive that fast food chains have made their children's meals healthier and added options like fruit and veg to the menu, but all too often kids go for options that are high in calories, fat, sugar and salt, particularly when they visit with their friends.

“We'd like to see all fast food restaurants providing nutritional information at the counter so that parents and older children know what they're eating.”