KIT Kats are to undergo a recipe change in a bid to make the York-produced bars more healthy.

Nestlé has announced that it is reformulating the Kit Kat following a three-year research programme at its innovation centre in York.

The new recipe will see 0.4g of saturated fat cut from each two-fingered milk chocolate bar, the equivalent of 3,800 tonnes of saturated fat being removed from the nation’s diet.

The reduction has been made by changing the recipe of the wafer filling.

York’s Nestlé Confectionery factory in Haxby Road will manufacture the new bars, which will be on sale from early next year.

The move by Nestlé comes as the firm signs up to the Department of Health’s new Responsibility Deal Pledge on saturated fats.

Ciaran Sullivan, managing director of Nestlé Confectionery, said: “This is the next step on the journey where we are improving the nutritional profile of our products.

“Kit Kat is our biggest confectionery brand and therefore the obvious choice to identify a sat-fat reduction.

“Improving the nutritional profile of Kit Kat does not come at the expense of quality and taste and consumers will continue to enjoy the same Kit Kat as they have for over 75 years.”

Bosses say the new Kit Kats are the latest in an “ongoing commitment” to improve the nutritional composition of its confectionery portfolio. As a result of this all Nestlé confectionery chocolate biscuit bars are low in salt and meet the Responsibility Deal 2012 salt targets.

Nestlé has also reduced the portion size of many of its products such as Kit Kat, Aero, Yorkie, Lion Bar, and Rolo and is working to expand its range of 99-calorie biscuit bars, which last year included the addition of Blue Riband Caramel, Aero Biscuit Peppermint and Aero Biscuit Orange.

More than a billion Kit Kat bars are made in the York factory per year, with the site producing up to six million every day.