It's a question that inevitably gets asked of Eddie Murphy and Martin Short, in their respective guises as Sherman Klump (of "The Nutty Professor") and Jiminy Glick (of "Primetime Glick"). But they're comics, and now the query is being put to the otherwise dignified Oscar winner ("Shakespeare in Love" . . . hello?) Gwyneth Paltrow. That is, what's it like to wear a fat suit? "Profoundly uncomfortable and suffocating," Paltrow recently told a gathering of reporters as she promoted her new movie, "Shallow Hal," about a fellow (Jack Black) who only sees the inner beauty of people, including the heavyset Rosemary (Paltrow). Okay, so it's a comedy. But the leading lady still suffered for her art. "They basically have to Krazy Glue (the fat suit) to your face," she explained. "It takes three hours to put on and about an hour to take off, and taking it off is almost worse, because these guys basically have to pour this syrupy, Vaseline-like, liquidity stuff around your eyes and mouth . . . ooh, it was terrible." The first time Paltrow, 29, was completely outfitted in the suit she was in the TriBeCa Grand Hotel in New York, and she decided to try out her new look on the public by walking through the lobby. "Here, I thought I was involved in this caper," she said, "but no one so much as looked at me." She thinks that had to do with the fact that people were being polite and not staring. "But, in fact," she said, "it was terribly isolating. It really upset me."