There's no violence, but definitely intense scenes and subject matter. There are many troubling aspects of the two sisters' ideas of their bodies; Frannie sleeps with guys she doesn't know very well and berates herself harshly for eating badly. Shelly wanders through a great deal of the film with sullen, dark eyes and an overly skinny body, sometimes binge eating and then violently vomiting.
When Shelly goes to a psychiatric ward for food issues, several other mentally challenged and troubled girls are there. One thin, rude and intense-looking woman who's visibly had a rough life is revealed to be in her early thirties (she looks like a mistreated twenty-something); she, and some of the other women, speak in ways that reveal them to be mentally absent. At one point Frannie goes to a severely disturbing website that viciously feeds on the mental trauma of anorexic people; the site shows disturbing images and comments from very sick people ("we are pigs fasting", "I want to be the skeleton in my doctor's closet", etc).
**SPOILERS** One of the most troubling scenes shows Frannie and her parents find Shelly dying on her bed from a drug overdose. The doctors tell them she can never be revived and the family's pain is palpable *END SPOILERS*
While this film is not a tragedy, there are very serious issues covered. I'd give it a PG-13 rating overall.