Energy drinks should be banned from schools because they are as damaging to young people as drugs, says a top Government advisor.
But he said: "Energy drinks are effectively another form of drugs. The amount of sugar and caffeine in these drinks is effectively allowing drugs into schools. We don't do that and in our view these drinks should not be a part of school life.
"They have hugely damaging effects on children. It affects their ability to concentrate, how they feel, and they have health effects."
Some 500ml drinks contain as much as 160ml of caffeine – the equivalent of four colas. And they also contain 12 teaspoons of sugar.
The impact of drinking them is palpable. Children's health adviser Claire Duggan told the BBC that pupils she had spoken to had reported feeling sick, shaky and dizzy after drinking the cans.
One school in Manchester is so concerned about pupils drinking energy drinks, that they have banned them.
Although the industry said the drinks were not aimed at children, they were not clearly labelled. Gavin Partington from the British Soft Drinks Association said the drinks 'are not designed for children'.
But it's clear that they are being drunk by children.
On BBC's Newsround website, pupils were asked if energy drinks should be banned in school.
There was mixed reaction.
Hamnah from Walsall, said: "I think students should be allowed to drink whatever they want but they should only be allowed to drink water in lessons."
Osha, from the West Midlands, said: "We're not allowed energy drinks at our school anyway. I agree with John Vincent, they can damage you concentration.
But Caitlin from Warrington added: "Energy drinks shouldn't be banned in schools because they keep you awake for the rest of the day, so you're more likely to pay attention."
However, Luke from Clevedon countered: "Energy drinks make me aggressive and give me a headache."
However, Kayleigh from Merseyside said a ban wouldn't make any difference.
She said: "Energy drinks have already been banned from our school but I don't think it makes a difference because people drink them outside school anyway."
In October 2012, we reported the story of 14-year-old Anais Fournier, who collapsed and died after having two cans of a fashionable caffeine-rich drink, billed by the makers as a 'killer energy brew'.
She suffered a heart attack which her family claims was brought on by 'caffeine toxicity' after she drank the Monster Energy drinks.
Now Mr Vincent wants an urgent review into such drinks to assess their impact on the health of young people.