The teenager at the centre of model Christie Brinkley's marriage split once starred in a bulimia documentary. DIANA BIANCHI, 19, has stunned America by confessing to having an affair with Brinkley's husband, architect Peter Cook, and now she has been exposed as a former bulimic, who previously went public with her eating disorder. Bianchi discussed her weight problems in high school student film BEAUTIFUL, which she co-wrote with fellow Southampton, New York student FAWN GETTLING (corr). The taped confessions were tracked down by researchers at US entertainment news show ENTERTAINMENT TONIGHT and producers aired segments on TV last night (21JUL06). In the documentary, Bianchi says, "Everyone expected me to be thin and beautiful. When I ate, I felt like I was letting them down. "Sometimes the pain was unbearable, and on occasion I would stop eating altogether... the guilt was unbearable. I felt disgusting and I felt I was letting people down, so I threw it up, and I threw up everything I ever ate after that and it became a habit." Bianchi, who is now an aspiring singer, insists she has since recovered from the eating disorder.