Stephen King's Thinner

The toughest and obese attorney Billy Halleck accidentally runs down and kills an old gypsy woman. Billy conspires with influential friends to sidestep responsability for the deed. Billy may have evaded punishments in the courts, but he can't escape justice at the hands of the victim's ancient father, who puts a curse on him. He starts losing weight, and cannot stop. Based on the Stephen King novel, written under the pseudonym Richard Bachman.