Parents are being urged to stop their kids using social media as addictive “junk food”.
Children’s Commissioner Anne Longfield rapped industry giants for trying to draw children into spending yet more time glued to tablets and smartphones.
The top adviser on child protection warned: “Children are in danger of seeing social media like sweeties, and online time like junk food.”
In an interview with the Observer newspaper, she took aim at Snapchat’s “Snapstreak” feature.
A streak is created when friends share photos on three consecutive days but it dies if a day is missed.
She said: “You find children saying they have 30 people they have to do every day and if they don’t, they drop the streak, and everyone will see.
“There are children who say they can’t not be online, and I think that’s really worrying.”
Ofcom says the internet now beats TV as kids’ top media pastime.
Three or four-year-olds spend an average of 8.5 hours a week online, for 12-to-15-year-olds it soars to more than 20 hours.
Her warning comes as the Government confirms new laws aimed at giving people a greater “right to be forgotten” online.
The Data Protection Bill will mean people can ask social media platforms to delete information they posted in their childhood.
The bill will also require people to give explicit consent for their information to be collected online, rather than firms relying on pre-selected tick boxes.
The bill, which was announced in the Queen’s Speech, will be introduced in Parliament when MPs and peers return from the summer break in September.
Digital Minister Matt Hancock said: “Our measures are designed to support businesses in their use of data, and give consumers the confidence that their data is protected and those who misuse it will be held to account.”