Teenagers are obsessed with their smartphones.

It's pretty much like my best friend.

Like I use it every single day.

And across the globe there are growing calls to restrict smartphones and social media for kids. the happens when teen smartphones are taken away from them.

And what is social media really doing to kids?

It's like radicalizing your friends and things like that like it changes their whole

perspective on things. Welcome to the documentary from the BBC World Service.

I'm Mariana Spring and with BBC Trending I'm investigating the impact of

social media on teenagers. I always have to have it next to me because like I won't get scared that I'm being left out or something.

That's Josh, a 14 year old from Birmingham.

Josh says he can be on his phone for up to 10 hours a day on the weekend.

My phone will be like constantly going off, which will wake me up, and then I'll have to check it

just to see if I'm like missing anything important and normally at 4 in the morning it's not that important.

And 14 year old Kia who also lives not too far from Josh is rarely off her phone either.

She got a smartphone when she was seven.

Sometimes I stay up all night maybe until about like 5 a.m.

watching Tik-tar, playing games or watching Netflix or anything like that.

And yeah I just just scroll and scroll and scroll. It's terrible.

According to data from the Centers for Disease Control and Prevention, the average 11 to 14 year old in the U.S. spends nine hours a day in front of a screen.

And research from Ofcom, the UK's media regulator, has found that a quarter of children as young as three and four in the UK own a smartphone. But that's all

about to change for Josh and Kia. As part of a not-very scientific experiment,

both of them are about to give up their phones, tablets and laptops for an entire week.

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