Who is Jay Hornbacher from Wasted: A Memoir of Anorexia and Bulimia and what is their importance?

Jay Hornbacher is Marya's father. While she is a young child, Jay is near paranoid in his over protectiveness of Marya. He desires a child who will never grow up. For this reason, he and Marya begin to have serious disagreements as she gets older and begins asserting her own personality. Jay seems to suspect that his daughter has an eating disorder. For instance, when Marya tells her family she has been throwing up, Jay responds that he had suspected this was the case. He also suspected that his daughter's car wreck the day before she is to go see the doctor, is caused by her anorexia.