Nicole Richie, co-star of The Simple Life, checks into treatment facility.

Nicole Richie, Paris Hilton’s partner on The Simple Life, has checked herself into a treatment facility for undisclosed reasons.

The wild daughter of famous singer Lionel Richie has been the subject media publicity regarding her waif figure for quite some time. While the star has denied any claim that she has an eating disorder her rep did say “she is working with a team of doctors and specialists whose focus is nutrition.”

Nicole and Paris Hilton, who had a very public split, have once again joined forces to bring The Simple Life back to the air.