Arguably the segment seeing the biggest proliferation of NPD is that for nut, seed and fruit-based protein bars from brands such as Grenade, Graze, Bounce and Kind.

Liam Mahoney, nutritionist at Grenade, which markets a range of protein bars and drinks, says the healthy eating category was "invariably non-existent" in many forecourts as recently as three years ago.

"Since then, consumer demand for heathier options, low-sugar snacks and innovative flavour options and formats has defined the category," he says. "The scale of the opportunity for operators is huge and presents incremental growth and enhanced profit margins, with rate-of-sale akin to low price point confectionery.

"To stay ahead of the curve, keeping up with NPD is on the agenda to ensure the latest flavours and pack sizes are available for customers."

Grenade’s products are featured in service stations operated by the likes of Welcome Break, Roadchef and Rontec, which operates 200 forecourt sites.

Rontec head of retail Michelle Levett says: "Since launching as a trial in a handful of forecourts in 2016, Grenade has quickly grown and become a leading brand within the protein category. The Grenade brand continues to go from strength to strength."

Earlier this year Grenade added a sixth flavour to its Carb Killa Shake range. Described as a "delicious smooth and creamy high protein, low sugar shake", the Peanut Nutter flavour is a convenient way for consumers to get additional protein into their diets without unwanted calories.