In Girl, Interrupted, what was Britney Murphy's obsession with chicken?

Question

Why did she hide it under her bed? And why did she only eat chicken? Also, what was the relationship between her and her father? Thanks!

Answer 1

She hid it under her bed because she didn't like other people watching her eating or seeing what she ate because she thought it was comparable to taking a dump in front everyone since what goes in must come out.  I don't think they explained why she only eats chicken in the movie.  They might have in the book, but I never read it. It was implied in the movie that she had a sexual relationship with her father.  

Answer 2

All I remember is that her father was having s*x with her or, at least, it was strongly implied. Daisy wasn’t able to face the fact that what her father was doing was wrong. She accepted it because it gave her the love and attention she craved from her father. But the activity was, most likely, what lead to her psychosis. If she also had an eating disorder (implied by taking the laxatives), some people tend to hide their food and gorge on it out of sight. Daisy wanted to be Daddy's perfect little girl. Daisy rejects Valium in the hospital because she doesn't like being associated with the other "crazies." But when she left the institution, she sort of surrendered to the demon thoughts of guilt and shame. It became too overwhelming for her outside of the hospital. She was never well enough to leave, thus the suicide.

EDIT: I just found this under the movie's IMDb Boards and I think it best answers your question:

The "fried chicken syndrome" was a manifestation of Daisy's unhealthy relationship with her father, which - one may surmise - could have been an important factor contributing to her mental illness. We know that Daisy was sexually abused by her father constantly. But she could not shake him off and was completely dependent on him emotionally. Perhaps the father was able to control her because he was the only one close to her who appeared to "love" her and care for her. In the film, Daisy's complete dependence on her father was shown by her refusing to eat anything other than the fried chicken smuggled in by her father. However, at the same time, inwardly, she felt guilty about her incestuous relationship with her father. So she hid the bones under her bed so as to hide the secret (about the chicken as well as about her father) from other people.