People with Phenylketonuria (PKU), a rare genetic disorder, are unable to metabolise phenylalanine, and therefore need to control their intake of all food and drink which contains this amino acid. Some of our reduced and no sugar, no calorie drinks like Diet Coke and Coca-Cola Zero Sugar are sweetened with aspartame, which contains a source of phenylalanine, and so we label all our products carefully to make this clear. 

Watch the experts at Nutrition and Health Live discuss the safety and benefits of sweeteners