Media mogul Simon Cowell has asked boy band One Direction to slow down.
Cowell, 55, who helped to put the group together on The X Factor, said he fears for the five-piece boy band, reported Contactmusic.
"They can't carry on doing the amount of stuff they've been doing for long because they'll burn out - it's a high-class problem. But they don't complain about working hard," he said.
The Steal My Girl hitmakers, who will embark on their third world tour next year, are "generous" to their fellow artists.
"They still come down to The X Factor, into song meetings and they will text me with ideas for the contestants.
They're generous to other artists. You don't see that very often. Most artists couldn't give a damn about anyone but themselves!," he said.