Starlet Lily Collins is looking skeletal these days and folks are wondering why. The already petite actor's shocking weight loss has to do with her role in a film called "To the Bone," a dark comedy about eating disorders. Yes you read that correctly--the movie pokes fun at anorexia. Yes it sounds insensitive, but hold up judging because the film has a purpose. Writer-director Marti Noxon plays on her real-life experiences to bust myths about eating disorders. "To the Bone," co-starring Keanu Reeves and Kathryn Prescott also highlights a bizarre occupational hazard of acting.

Lily Collins owns the part

"To the Bone" follows a young artist who, in response to life stresses, spirals into anorexia. Her doctor, Keanu Reeves, attempts to help the young woman. As part of her treatment, she enters an eating disorder clinic. She encounters other patients dealing with bulimia (binge-purge disorder) and other eating conditions. Collins had to lose weight for the part but also develop mannerisms and posture to make herself look thinner. The young actress succeeds, all too realistically:

Lily Collins proves obesity isn't the only weight-related health scare

Everywhere, you read about the dangers of obesity. Everyone's talking weight loss and different diet plans to achieve that.

Celebrities flaunt skinny, and some, like Mariah Carey and Kim Kardashian, brag about dangerous ways to lose weight. But less attention is given to equally scary conditions on the opposite end of the spectrum. Anorexia killed Karen Carpenter and Angelina Jolie is known to battle eating problems. "To the Bone" is part comedy and part docu-drama, using humor to address myths about this quiet killer.

The film will be entered into the Sundance Film Festival competition.

Lily Collins: life imitates art

Other actors have shed a lot of weight to play certain parts. Liam Neeson, Adam Driver and Andrew Garfield got super skinny to portray tortured Jesuit missionaries in Martin Scorsese's film "Silence." To do so, they lived an anorexic lifestyle.

It would be interesting to know what, if any, lingering health problems they sustained. Is the effect on the body any different if you starve yourself for an emotional condition or a role? Are the dangers the same if you have an eating disorder or just play someone who does?