
She's failed to put on the pounds she lost during a gruelling tour this summer.
And apparently band bosses are starting to fret over how slim Sarah - whose hits with the girls include Something Kinda Ooh - is looking.
An insider told me: "All the girls lost weight on the tour - 35 gigs in four months will do that to you.
"As soon as it finished in August they were told to look after themselves.
"Sarah's the only one refusing to and now we're all worried just how skinny she's got."
But the girls were in full swing last night with a £50,000 champagne bash at Kitts nightclub in London as they prepared to top the charts today with new single The Promise.

This article has 5 comments
The stick insect is not a good look... You have a huge fan base of young girls, you owe it to them to show a healthy young woman as a positive role model... women are supposed to have curves and breasts, that is why we are called woman and not man. go and get yourself pie and chips.
By Donna. Posted November 21 2008 at 12:30 PM.
No, it actually seems like Cheryl has gone and got herself a stylist and a great spin doctor since she joined the X Factor. Every story that comes out about her has a positive spin, and it's well known that her and Sarah never got on, so I suspect Sarah is being used to deflect any negative attention. Cheryl gets sympathy for weight loss because she is "heartbroken", but Sarah is "attention seeking". Yeah right, I've noticed that every positive story about Cheryl has been followed by a negative one of Sarah. Good work Spin Doctors!! And stylist, because that girl was chav city a few months ago.
By dee. Posted October 29 2008 at 1:09 PM.
has anybody noticed whenever Cheryl is getting all the headlines, Sarah does something to get herself in there within a couple of weeks?
By nicole. Posted October 26 2008 at 8:34 PM.
sarah is developing the body of amy winehouse. stop it and start looking after yourself
By wayne stockton. Posted October 26 2008 at 9:51 AM.
all the girls in girls aloud are very slim kimberley looks the more healthy sarah has gone to far she needs to eat more healthy gain a few pounds skin and bone is not attractive and not a good role model for young girls
By jenny machin. Posted October 26 2008 at 9:19 AM.