Half of young people who consume energy drinks suffer negative side effects ranging from rapid heartrates to seizures, a study suggests.

Scientists say more should be done to restrict young people buying the drinks after 55 per cent of 12 to 24-year-olds surveyed reported negative health impacts.

Canadian researchers asked 2,055 youngsters about their consumption of energy drinks like Red Bull and Monster, which can contain as much caffeine as five cups of coffee.

Of those who consumed the drinks, nearly a quarter (24.7 per cent) said they had experienced a fast heartbeat or struggled sleeping (24.1 per cent), while 0.2 per cent even reported suffering seizures.

Study lead Professor David Hammond said: “The number of health effects observed in our study suggests that more should be done to restrict consumption among children and youth.”

Prof Hammond, from the University of Waterloo in Ontario, said energy drinks are more dangerous than other caffeinated drinks because of the way they are consumed.

And the negative effects of caffeine in energy drinks was ‘significantly more prevalent’ than in sources including coffee, the study showed.

Prof Hammond added: “Most risk assessments to date have used coffee as a reference for estimating the health effects of energy drinks, however it is clear these products pose a greater health risk.

“The health effects from energy could be due to the different ingredients than coffee, or the ways in which they are consumed, including with alcohol or during physical activity.

“Regardless, the findings suggest a need to increase surveillance of health effects from these products.”

The research also revealed 18.3 per cent of young people experienced headaches after consuming the drinks, while 5.1 per cent reported nausea, vomiting or diarrhoea.

A further five per cent sought medical attention and 3.6 per cent reported experiencing chest pains.

And the ‘vast majority’ of those who experienced adverse effects had consumed less than the recommended maximum of one or two drinks, the study showed.

Prof Hammond said: “At the moment, there are no restrictions on children purchasing energy drinks, and they are marketed at the point-of-sale in grocery stores, as well as advertising that targets children.”

Energy drinks normally contain about 80mg of caffeine per 100ml – which is roughly the same as three cans of Coca-Cola or one cup of instant coffee, according to the UK Food Standards Agency.

But many also contain high amounts of sugar and come in cans which contain 500ml of drink.

Campaigners in Britain have urged the government to restrict sales of the drinks to under-16s.

Waitrose recently announced it will refuse to sell the drinks to under-16s from March 5.

The supermarket’s director of technical and corporate social responsibility, Simon Moore, said: "As a responsible retailer we want to sell these products in line with the labelling guidance.

"These drinks carry advice stating that they are not recommended for children, so we're choosing to proactively act on that guidance, particularly given the widespread concerns which have been raised about these drinks when consumed by under 16s."