is reportedly following an extremely restrictive diet and exercise regimen at the moment.
The pop star co-judges on Simon Cowell
's hit US TV talent show The X Factor
with Simon, Demi Lovato
and L.A. Reid.Britney
began her post last week and is committed to remaining in great shape throughout the season.
has been on an extreme diet and exercise regime," a source told British newspaper The Sun. "She has been cutting out ...