Campaigners in the war on sugar today turned their fire on energy drinks, claiming the products contained “excessive and worryingly high levels of added sugars.”

Research by Action on Sugar showed that out of a total of 197 energy drinks surveyed, 78% would receive a red label for sugars per serving, with more than half containing the same amount or more sugar than Coca Cola per 100ml, or the equivalent of nine teaspoons of sugar per 330ml can

It name the worst offender as Rockstar Punched Energy tropical guava flavour, with the equivalent of 20 teaspoons of sugar per 500ml can.

The report also cited products which have far less sugar in them, demonstrating there is no reason for such high levels. Monster Khaos energy and juice contained 50% less sugar than the highest sugar containing energy drinks, it said.

The level of sugars in a typical can is disgraceful,” said Kawther Hashem, a nutritionist at Action on Sugar. “Free sugars increase the risk of obesity, type 2 diabetes and dental caries and we need to protect children and teenagers from drinking these products. “

However, Gavin Partington, director general of the British Soft Drinks association, said: “These products are called energy drinks for a reason - they deliver a caffeine or glucose-based energy boost.

“They are now available in a variety of types, flavours and sizes, including a range of low and no calorie options, so that consumers have a much wider choice.

“BSDA members do not promote energy drinks to children under 16 and all products are clearly labelled in compliance with EU regulations.”