Sales of Sprite have nosedived since its sugar content was cut by a third, exclusive analysis by The Grocer has revealed.

Stevia was added to the recipe in March 2013 to turn around falling sales and in the wake of pressure on soft drinks players such as Sprite’s brand owner Coca-Cola Enterprises by the health lobby.

But Sprite’s decline has accelerated to 9.4% on volumes down 9.2% [IRI 52 w/e 4 March], from 6.4% on volumes down 7.3% the previous year, despite a triple-digit hike in spend on ad space for Sprite [Ebiquity 52 w/e 31 December], though deals on the brand have fallen 6.3% in the past year [].

“It’s a very competitive category,” said Caroline Cater, operational marketing director at CCE.

The stevia switch attracted “consumers who don’t drink as heavily” to the brand. Sprite will be the focus of a new marketing push this year, she added.

Diet Coke also suffered, with sales falling 2.4% on volumes down 3.8%, as ad spend was for the first time overtaken by spend on Coke Zero. “We’ve had a strong year with Coke Zero,” said Cater, pointing to its 20.5% growth on volumes up 21.2%.

However, diet and ‘healthier’ carbonates are still being outgrown by traditional pop.

Five of the 10 best-selling carbonates, including own label, are now zero or low-sugar brands. They have achieved combined growth of 2.5% on volumes up 1.3% in the past year.

Meanwhile, the four best-selling full-sugar brands (Coke, Pepsi, Fanta and Dr Pepper) delivered combined growth of 4.3%, worth £42.1m in new sales, on volumes up 2.5%.