Radio 1's Scott Mills has opened up about how the One Direction superstars have changed since they first burst onto the scene as contestants on 'The X Factor' a few years ago. 

Speaking exclusively to Yahoo! OMG about the five lads ahead of their Radio 1 Big Weekend performance, which will take place in Glasgow tomorrow and on Sunday, the DJ admitted that they have changed, but in the best way possible:

"I would say that One Direction have really changed since the 'X Factor'. They've been in the spotlight since they were very young and I think everything about them is different now. Their styling is completely different and they’ve just grown up."

"They're definitely still down to earth – they’re just like normal lads still. I mean, everything around them is ridiculous.  But when you’re just with them there on your own for eight hours, nothing really has changed."

Mills went onto add that he's the only person to be doing an interview with the heartthrobs so the questions will be super juicy: "I actually get to do the only interview that they’re doing so I’m quite excited about that. I’m going to be asking LOADS of juicy stuff – I’m just working on my questions now actually."

"I did this thing called 1D day last year – I know them well enough to ask them questions that they might not be expecting. I might get a bit more lee-way than some people."

Watch footage of One Direction performing on their Where We Are tour below: