"I've still got the scars on my knuckles from where I put my fingers down my throat," the 34-year-old actress told Easy Living magazine for its September issue.
The “Pursuit of Happyness” and “Mission: Impossible II” actress said her obsession started as early as 14 when she trained in ballet and ate "nothing but cottage cheese."
Newton then found herself in a string of abusive relationships that culminated in an eating disorder when she was in her 20s.
The now-married mother of two said she eventually sought help while in Los Angeles shooting a film.
"I saw a therapist for the first time," she recalled. "After that first session, I never threw up again. I had made the connection between shame and self abuse."