Although fruit smoothies are packed full of fresh fruit and fibre – and count towards one of the all-important ‘five a day’ – they actually contain heaps of sugar, particularly the banana-based varieties. A staggering seven teaspoons of sugar can be found in many 100ml servings – that’s more than in a cola!

They are also high in acid and this is where the problem lies as far as your teeth are concerned.

A large quantity of fruit is required to make even a small smoothie and because it is concentrated the acid can literally wash away tooth enamel.

Advice is to limit the amount of smoothies you and your family consumes and if you can’t resist, make sure you drink them through a straw, which keeps the acid away from your teeth. You should also follow them with a small cube of cheese, which helps to bring down the acidity levels in your mouth. Ideally for children you should dilute juices, give them at mealtimes and do not brush for at least one hour after drinking the juice (or taking acidic food), because your tooth enamel will be temporarily softened and brushing can damage it.