Children in England are to be banned from buying energy drinks under Government plans.
Youngsters in the UK reportedly consume more of the high-caffeine, sugar-loaded drinks than other children in Europe and the habit is harming their health and education, ministers fear.
The restrictions will apply to drinks with more than 150mg of caffeine per litre, like popular brands Red Bull, Monster and Relentless.
Excessive consumption has been linked to a host of health and behaviour problems in children, from headaches to hyperactivity.
Many major retailers already refuse to sell to under-16s but the Government intends to introduce a blanket ban under plans put out for consultation, with restrictions on either under-18s or under-16s being considered.
A Government source was adamant the ban would come into force, saying: "It's a question of how, not whether, we do it."
The issue has come under scrutiny recently owing to a booming energy drinks market, high-profile calls from campaigners and figures like TV chef Jamie Oliver, and the low cost of some types compared with general soft drinks.
Four cans of generic 250ml energy drink can be bought for as little as £1, for example.
More than two-thirds of 10-17 year-olds and a quarter of six to nine year olds consume energy drinks, according to No 10.
While many major retailers do not sell to under-16s, just 21% of the UK grocery market, including corner shops, are signed up to voluntary restrictions, No 10 said.
Public Health Minister Steve Brine said: "We all have a responsibility to protect children from products that are damaging to their health and education, and we know that drinks packed to the brim with caffeine, and often sugar, are becoming a common fixture of their diet.
"Our children already consume 50% more of these drinks than our European counterparts, and teachers have made worrying links between energy drinks and poor behaviour in the classroom."
UK Energy drink sales jumped by around one-fifth (19%) between 2012 and 2017, according to analysis from market researchers Mintel.
Some 669 million litres were sold last year with total sales estimated at £1.65 billion, the firm added.
Although sugar-containing versions remain the most popular, many firms offer reduced or zero sugar products.
The sugar tax introduced in April has contributed to many brands focusing on low-sugar recipes to avoid the levy, Mintel noted.
Professor Russell Viner, President of the Royal College of Paediatrics and Child Health, said: "There is no evidence that energy drinks have any nutritional value or place in the diet of children and young people.
"The growing market for energy drinks and potential for harm to children and young people clearly warrants further scrutiny."
Tam Fry, of Action On Sugar, said:"It is astounding that the Government feels that a consultation is required.
"It has been told for years that these drinks a quite unsuitable for children even if they play a lot of sports.
"We need a government that leads rather than going cap-in-hand to the court of popular approval since your average man-in-the-street knows little of the danger that these drinks are to young people."
Existing industry labelling guidelines require any soft drink with more than 150mg of caffeine per litre to carry a high-caffeine content warning and state it is not recommended for children.
Scotland, Northern Ireland and Wales have the power to implement their own bans.
Jenny Oldroyd, deputy director for obesity, food and nutrition at the Department of Health and Social Care, has previously said: "Around a quarter of adolescents are consuming more than three energy drinks in one sitting, so it's that high level of consumption that concerns us."