One of Britain’s largest confectionery makers is to cut the number of calories in its chocolate snacks in a bid to help tackle the childhood obesity crisis.

Cadbury’s is to announce it will reduce the amount of calories in many of its children’s products to 100 by reducing the size of individual snacks.

While some prices for the smaller packets may fall the firm admitted some may stay the same, effectively driving up the cost by weight of children’s chocolate treats.

But the US-owned firm said the move will remove billions of calories from the market and was vital to help parents and grandparents control the amount consumed by children on a daily basis.

The move will see favourites such as Curly Wurly, Fudge and Chomp, reduced in size by the end of 2020 to bring them down to the 100 calorie cap without changing their ingredients.