The "ground-breaking" sugar tax on soft drinks has come into force in the UK. Ministers and campaigners believe it has already proved to be a success with many firms reducing sugar content ahead of the change. But others say it is still too early to judge the impact. Leading brands such as Fanta, Ribena and Lucozade have cut the sugar content of drinks, but Coca-Cola has not. The introduction of the levy means the UK joins a small handful of nations, including Mexico, France and Norway, which have introduced similar taxes. Reaction to the new tax has been mixed with many consumers arguing that government should not interfere in what they consider to be a personal choice. All age groups are consuming too much sugar, with teenagers the worst offenders. They get a quarter of their sugar intake from soft drinks.Estimates by the Treasury based on market data suggest 50% of manufacturers have reduced the sugar content of their drinks. Earlier this year Coca-Cola announced it will cut the size of its 1.75l bottle to 1.5l and put up the price by 20p. The company said it had decided not to change its classic recipe because "people love the taste and have told us not to change".