Lily Collins stunned by reactions to her skinny look for To the Bone film

Actress Lily Collins was left stunned and disturbed when a pal complimented her skinny frame as she prepared to play an anorexic in her new film.

The Mirror Mirror star, who has battled an eating disorder in the past, admits she was taken aback by all the reactions to her look as she started losing weight to play Ellen in director Marti Noxon's hard-hitting new movie To the Bone.

But it was one comment a friend made that really shocked the 28-year-old.

"Someone I’ve known for a long time said to me, 'Oh, wow, look at you!'" Lily told Net-a-Porter’s The Edit magazine. "I tried to explain (I had lost weight for a role) and she goes, 'No! I want to know what you’re doing, you look great!'

"I got into the car with my mom and said, 'That is why the problem exists'."

Lily, who is the daughter of rocker Phil Collins, struggled with body image throughout her teens, explaining, "From a young age, I’ve had a desire to put forward this perfect image... Even though there was all this un-prettiness going on inside of me, I wanted to make sure that my appearance and composure were a certain way. I imagined that people knew I had these secrets and they’d be judging."

As she prepared for To the Bone, the actress was also rejected by various magazine bosses - because she was considered too skinny.

"I was about to embark on press for (film) Rules Don’t Apply and I was told that a lot of media did not want to put me in their magazines... looking the way I did, even though it was for a movie," she adds. "No one knew my connection to the disorder, and, at the time, I was super upset because I thought, 'This is a huge moment for me and I can’t maximize on it'.

"I told my publicist that if I could snap my fingers and gain 10 pounds right that second, I would give anything to do that. I never thought I'd ever say anything like that!"