Campaigners are calling for a ban on the sale of energy drinks to children after finding their sugar and caffeine content remains high despite reformulation ahead of the soft-drinks levy.

While some manufacturers have reduced sugar in the drinks ahead of the levy taking effect in April, the large can and bottle sizes means youngsters are still consuming too much unnecessary sugar and caffeine, according to the study by Action on Sugar (AoS), published in the journal BMJ Open.

The energy drinks surveyed show a 10 per cent reduction in sugar from 10.6g to 9.5g per 100ml and a six per cent reduction in calorie content per 100ml between 2015 and this year, AoS said. But it found typical serving sizes of energy drinks were larger than other sugar-sweetened drinks at an “excessive” 500ml, while the average sugar content in energy drinks in both 2015 and this year per serving was more than an adult’s entire maximum daily recommendation