Nicole Richie, our favorite celebutante waif, is finally listening to all the people who say she's too skinny. The star of The Simple Life is checking herself into a clinic for "testing and observation" to find out why she's not gaining any weight, despite all the healthy full meals and ice cream she's been eating lately (her people insist she doesn't have an eating disorder).

Nicole's stay could mean a delay in the shooting of the fifth installment of Simple Life, which is set to begin taping in the next couple of weeks. This batch of shows reunites Nicole with Paris Hilton, working as camp counselors. We don't think it'll be a "fat camp." That would be too cruel.

The last time we saw Nicole and Paris on The Simple Life, they appeared in separate segments, refusing to appear together because of their now-infamous feud.

We all have David Letterman to thank (?) for the reconciliation and reunion.

--Tabloid Baby