Chocolate bars are likely to shrink by a fifth in the next three years after Public Health England told sweet manufacturers they could meet obesity targets by cutting product size.

Today PHE published new guidelines which call on food manufacturers to reduce the sugar content of cereals, breakfast goods, yoghurts, biscuits, ice creams, sweet spreads and confectionery by 20 per cent by 2020.

The cuts are intended to reduce the number of children who are overweight or obese by the end of the decade and take 200,000 tons of sugar out of the British diet each year.