The main cause of tooth decay is not the amount of sugar or acid in the diet, but how often it is eaten or drunk. The more often your child has sugary or acidic foods or drinks, the more likely they are to have decay. So it is important to have sugary and acidic foods just at mealtimes. If you want to give your child a snack, try to stick to cheese, vegetables and fruit. Try to limit how much dried fruit you give as it is high in sugar and can stick to the teeth.
Don't give them drinks containing sugars, including fruit juices, between meals. Give them water or milk instead. For babies, don't add sugar to their drinks, or to foods when you introduce them to solids.
It is also worth remembering that some processed baby foods contain quite a lot of sugar. Try checking the list of ingredients: the higher up the list sugar is, the more there is in the product. Generally anything ending in ‘ose' is a sugar, for example: fructose, glucose, lactose or sucrose. Thorough brushing with a fluoride toothpaste last thing at night, and at least one other time during the day, will help to prevent tooth decay.