Cadbury is to make a new Dairy Milk bar that contains 30% less sugar than the current version - in response to the obesity crisis.
The confectioner says it'll go on sale next year - and claims it's the "most significant innovation in the brand's history".
It's also planning similar moves with other products including Oreo, Wine Gums and Jelly Babies.
In the new bar the sugar content will be 39g per 100g, down from 56g per 100g in the traditional one, however the calorie content will be similar.
Glenn Caton, Mondelez International president for Northern Europe, said the science behind the reformulation was a "trade secret" but the taste of the new bar as "incredibly similar" to the original.
He said: "It tastes very, very close to the original but a little less sweet. It's been tested extensively on consumers and they love it."