Freakshakes and milkshakes which contain "grotesque" levels of sugar and calories should be banned, according to a campaign group.
Some of the worst offending items available in UK restaurants contain more than half of an adults daily recommended sugar intake and more than 150g of sugar, which is equivalent to 39 teaspoons of sugar or as much sugar as in 14.7 KitKats.
Action on Sugar is calling for a ban on all freakshakes - milkshakes that also contain chocolates, sweets, cake, cream and sauce - and milkshakes that exceed 300 calories per serving.
However, after surveying freakshakes and milkshakes available in UK restaurants only six of 46 (for which information was provided) would not be banned under the 300 calorie limit.
Toby Carvery’s Unicorn Freakshake topped the list of sugary freakshakes and milkshakes, with one serving coming in at 1,280 calories and 156g of sugar.
The 39 teaspoons of sugar is more than six times the recommended amount of sugar for a 10-year-old to consume in a day, and is equivalent to more than four cans of Coke or 14.7 KitKats.
Meanwhile, 90% of the 41 milkshakes surveyed in shops would receive a "red" (high) label for excessive levels of sugars per serving.
The milkshake with the highest levels of sugar was a 400ml bottle of Müller Milk Frijj Chocolate Flavour, which contains 304 calories and 42.8g of sugar, equivalent to 11 teaspoons of sugar or four KitKats.
Along with the chocolate flavoured milkshake, Müller's Fudge Brownie, Cookie Dough, Strawberry, and Banana Frijj milkshakes were the top five most sugary milkshakes which can be bought in shops, all containing between 10 and 11 teaspoons of sugar each.
While some of the sugars in the milkshakes and freakshakes are lactose sugars which occur naturally in milk, nutritional labelling does not differentiate between these and added sugar.
However, the vast amounts of sugar in the drinks surveyed were added sugars.
It is recommended that UK adults eat no more than 2,000 calories per day and no more than 90g of sugar, while children aged between five and 10 should eat 1,800 calories per day and no more than 85g of sugar.
Action on Sugar said the survey’s findings revealed “grotesque levels of sugar and calories” and called for a ban on all milkshakes that exceeded 300 calories per serving.
The campaign group's calls far-exceed the recommendations by Public Health England (PHE) which is asking companies to reduce the amount of sugar in their products by 20% by 202, but would still leave many of the products surveyed with incredibly high levels of sugar.
But Graham MacGregor, professor of cardiovascular medicine at Queen Mary University of London and chairman of Action on Sugar, said the cuts should go further.
“These very high calorie drinks if consumed on a daily basis, would result in children becoming obese and suffer from tooth decay – that is not acceptable," Mr MacGregor said.
“Despite milkshakes being incorporated into the Public Health England’s Sugar Reduction Programme as part of the Government’s childhood obesity plan, it is clear from our survey that much more needs to be done than a 20% reduction.
“These high calorie milkshakes need to be reduced immediately below the 300kcal per serving.”
Dr Alison Tedstone, chief nutritionist at PHE, said: “Milkshakes can contain significant amounts of sugar – consuming too much sugar contributes to children leaving primary school overweight or obese, and suffering with tooth decay.
“The food and drink industry – including restaurants, manufacturers and retailers – has a key role in helping to tackle this by reducing the amount of sugar we buy and consume, and we hope to see them step up to the challenge.”
A spokesperson for Toby Carvery said: “Freakshakes only feature on our main menu and are not targeted at children.
“We share our nutritional information online for guests to access and we are very mindful of our role in helping guests’ make informed decisions about what they eat and drink while dining with us.
“We also regularly work with our suppliers to explore ways we can reduce sugar levels in our dishes and have also committed to the Public Health England Sugar Reduction programme.”
While a spokesperson for Müller said: “We know that for health conscious consumers the choice of reduced sugar is important, without compromising on taste.
"That’s why we introduced a Frijj zero added sugar range.
“Milk contains naturally occurring sugars in the form of lactose but we would stress that it is also a natural and nutrient rich product, containing essential nutrients such as protein, calcium and vitamins.”