Dentists are calling for a reduction in sugar of around 75%, equating to just four teaspoons a day. 

A cap at that level would equate to half a can of Coca-Cola, which contains nine teaspoons, or two McVitie’s digestives.

The World Health Organisation (WHO) recently called for a reduction in consumption to around 5% of daily calories, which equates to six teaspoons.

While fluoride-added toothpastes have reduced tooth decay in some countries, treatment still accounts for 6% to 10% of total health costs. A new study argues that a significant improvement will only be made with a major reduction in sugar consumption and a focus on how much is added to food and drink in production.

The report estimates that a 20% tax on fizzy drinks, which would raise the price of a can from 70p to 84p, would cut the number of overweight Britons by more than 250,000.

The average sugar consumption per day is around 14.5 teaspoons for adults and 19 teaspoons for teenagers. The findings will fuel calls for a sugar tax, much like that on tobacco.

Nutritionist and campaign director of Action on Sugar Katharine Jenner backed the study findings, saying: “Added sugars are completely unnecessary in our diets and are strongly linked to dental decay as well as to obesity and type II diabetes.”