CLEARFIELD, Pa. Jan 17, 2005 — Kate Stelnick may weigh only 100 pounds, but her appetite is remarkable. The college student from Princeton, N.J., is the first to meet a restaurant's challenge by downing its six-pound hamburger and five pounds of fixins' within three hours. Stelnick didn't eat for two days to prepare for the challenge. "I felt very full, but I was too excited that I actually ate it to notice," Stelnick said. Stelnick, 19, made the five-hour drive to Denny's Beer Barrel Pub with two friends from The College of New Jersey on Wednesday, after they saw pictures...