Augustus Prew lost over a stone to play the teenage Kevin Lewis. He also wore shoes deliberately too small and refrained as much as possible from eating as Lewis had told him that he spent most of his teenage years permanently hungry.
The level of abuse depicted in the film is considerably toned down from what was in the book.
Kevin Lewis experienced difficulty being on set when Natascha McElhone was playing his abusive mother as he found the resemblance too unsettling.
The first day of filming at the South Oxhey housing estate outside of London was interrupted when the police discovered a body in the nearby woods.
The screenwriter and development producer Mark Thomas spent months adapting the novel "The Kid" alongside its author Kevin Lewis. Thomas then approached Nick Moran to direct the film after taking Lewis and Ed Atkinson to view the film "Telstar" which was Morans debut film.