Vacherin’s range of sustainable meals have been adapted so they include less meat and more veg.

No more than 30% of a dish should comprise animal proteins with an upper limit for meat or fish content set at three ounces. At least 35% of each meal should be fruit and veg with no processed ingredients.

Meals meeting the new criteria will carry the “A Greener Choice” logo. Zoe Stennett-Cox, the catering firm’s lead on sustainability, said the changes are not a gimmick, “but a real commitment to offer customers at our sites responsible food options every single day”. Demand for healthier, vegetarian and flexitarian options is increasing all the time, she added.

Indeed, data published by Nielsen just before Christmas showed that the British public’s desire to eat more healthily has “propelled fresh fruit and free-from to become the fastest-growing products at supermarkets” in 2016.

“The nation is increasingly concerned about diet and health – over four in 10 Britons now actively avoid certain ingredients in what they eat and drink – which is reflected in fresh fruit and free-from being the fastest-growing categories,” said Mike Watkins, Nielsen’s UK head of retailer and business insight.

Free-from’s growth means it is worth £772.2 million a year, making it a bigger category than instant coffee and sparkling wine. “To some, free-from may still have the air of an ‘alternative’ or niche category but it’s now nearly 40% bigger than a signature staple of British consumption – tea,” Watkins added