As the coffee-to-go boom continues, health campaigners are calling for a ban on extra-large cups of hot flavoured drinks in coffee shops and stores, in a bid to slash sugar consumption.

According to new research from the charity Action on Sugar, 98% of hot flavoured drinks currently on sale would receive a ‘red’ (high) label for excessive levels of sugars per serving.

The charity analysed sugar levels in nine of the UK’s leading high-street coffee chains and franchises including Starbucks, Costa Coffee, Café Nero and Greggs.

Starbuck’s Hot Mulled Fruit - Grape with Chai, Orange and Cinnamon Venti was found to contain 25 teaspoons of sugar in its extra-large cup - more than three times the maximum adult daily intake of free sugars. A large Costa Coffee Chai Latte was found to contain 20 teaspoons of sugar.

From the entire out-of-home hot drinks surveyed, 55% were found to contain the equivalent, or more than, the maximum daily recommended amount of sugars for an adult and teenager (30g – or seven teaspoons a day).

“It is time coffee chains stopped serving extra-large cups of sugar-laden hot drinks,” the charity said.

With the imminent release of the government’s Childhood Obesity Strategy, Action on Sugar is calling for stricter product reformulation, with a target of reducing sugar by 50%, a ban on promotions and marketing of unhealthy products and a 20% tax on sugar-sweetened drinks.

Kawther Hashem, nutritionist and researcher for Action on Sugar, said: “These hot flavoured drinks should be an occasional treat, not an ‘everyday’ drink. They are laden with an unbelievable amount sugar and calories and are often accompanied by a high sugar and fat snack. It is not surprising that we have the highest rate of obesity in Europe.”

The charity is calling on the government to create a new “agency for nutrition” and uniform colour-coded labelling on all foods and drinks, both bought in stores and out-of-home.

Londis retailer Jatinder Sohata from the Isle of Sheppey said he was concerned by the call to action.

“First we had tobacco, then soft drinks, and now coffee, where will it end? Coffee to go is now a major part of my business and in fact just today I have launched a new loyalty card offering shoppers their ninth cup for free.

“News like this is a big worry as categories such as hot coffee to go are fantastic profit generators and will be incredibly helpful in offsetting new costs such as the National Living Wage. My one consolation is that we don’t offer the extra large sizes that seem to be coming under attack here and shoppers add their own sugar and syrups to the drinks so it’s personal choice,” he added.

There are now more than 16,500 coffee outlets in the UK, with the major chains growing by about 100 units a year. Turnover in the out of home coffee market is growing by 11% year on year, and two-thirds of this growth is from non-specialists, including fast food outlets, such as McDonald’s but also convenience stores.