A new report from a British campaign has made a not-so-sweet discovery: Flavored drinks served at mega-chains in Britain -- like Starbucks, Costa and Pret a Manger -- contain a “shocking” amount of sugar -- up to 25 teaspoons in one serving. That’s three times the amount of sugar in one can of Coca-Cola and over three times the maximum adult daily intake recommended by the American Heart Association, CNNMoney reported. 

Although the report focused on drinks sold in Britain, nutritional information published on the companies’ websites reportedly revealed that sugar levels are similar to those in the United States. The report, from the group Action on Sugar, stated that 98 percent of hot flavored drinks sold at major coffee chains in Britain would have received a label for excessive levels of sugars per serving sold. Out of the 131 hot flavored drinks analyzed, 35 percent contained the same amount of sugar -- or more -- as a can of Coca-Cola, according to a news release.

“These hot flavored 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 [high-]fat snack. It is not surprising that we have the highest rate of obesity in Europe. Our advice to consumers is to have a plain hot drink or ask for your drink to contain a minimal amount of syrup, preferably sugar-free, in the smallest serving size available,” said Kawther Hashem, a registered nutritionist and researcher for Action on Sugar.

RTX12TYK A barista makes drinks inside a newly designed Starbucks coffee shop in Fountain Valley, California Aug. 22, 2013. Photo: Reuters

The most sugary beverages, according to the report, included Starbucks’ hot mulled fruit (grape with chai, orange and cinnamon), containing 25 teaspoons of sugar. Starbucks’ vanilla latte and caramel macchiato contained eight teaspoons of sugar each. In response, Starbucks told the Guardian that it was committed to reducing added sugar in its indulgent drinks by 35 percent by the end of 2020. 

"These results highlight the need for more transparency on sugar content and compulsory labeling of sugar content. Drinkers deserve to know how much sugar they are consuming,” said Nicola Close, chief executive of the Association of Directors of Public Health. 

The World Health Organization recently suggested cutting the recommended sugar intake for adults in half, to about 25 grams, as health campaigns have increasingly scrutinized excessive sugar contents.