Demi Moore -- Skin and Bones and Wedding Ring

Demi Moore looked to be in desperate need of a good meal when she hit the N.Y. premiere of her new movie last night ... and according to Joan Rivers, it's because Demi BARELY ate anything on her flight in from L.A.

Joan was on the same flight as Demi ... and after she got off the plane, Rivers sold out her co-passenger to the paparazzi ... telling them that all Demi ate on the 6-hour flight was an apple ... and some water.

By the time Demi hit the red carpet ... it was Moore who was feeding the media, by sporting her wedding ring ... despite rumors that her marriage to Ashton Kutcher is on the rocks.