Thinner

More about the book

Billy Halleck commits vehicular homicide when his lack of attention to driving results in the death of an old lady on the street. Overweight Halleck is a lawyer with connections, though, and gets off with a slap on the wrist. After his trial, a gypsy curses him with a single word, "Thinner." Halleck begins to lose weight uncontrollably and must pursue the band of gypsies who are responsible for his dwindling condition. source: stephenking.com