{blackbabes} Zoë Kravitz Relives Her Own Eating Disorder Battle in New Movie Role

Mena Suvari / Models / Nascar / Nashville / Natalie Portman

For years, Zoë Kravitz struggled with a painful secret.

From the time she was 13 years old until about two years ago, the 26-year-old says she suffered on and off with an eating disorder.

"It was really, really bad in high school," Kravitz tells PEOPLE. "When I was 16, 17, 18, it was at its worst and it trickled into my early 20s."

One of the roots of the issue was comparing herself to other people on television and in magazines.

"I think it's important for people to hear that people within the industry feel that, too," she says. "I will always compare myself to the beautiful blond bombshell with huge boobs. It's the name of the game."

Kravitz says she knew she had a problem when she was around 17.

"You convince yourself it's okay but you know you have a problem," she says. "Like trying not to eat and throwing up and then binging and purging, you know you have a problem."

The actress is now reliving those years, bringing her experience to her role as Marie, an anorexic girl in the film The Road Within.

"I've dealt with my own issues with food and I was just getting ready to confront that stuff again and kind of go through the motions of where that stemmed from for me and what that meant for me," Kravitz says.

The role required Kravitz to lose weight all over again, but this time in a healthier way guided by a nutritionist. She says she got down to 90 lbs. by doing cleanses and eating pureed vegetables a few times a day along with a lot of cardio.

"It was intense and I kept that diet up for most of the shoot because I was continuing to lose weight throughout filming so at the end I could do the shot where you kind of see my body exposed and you could see how thin Marie is," she says.

Slipping into Character

Due to the nature of the role and given her past, Kravitz says her friends, and parents Lenny Kravitz, 50, and Lisa Bonet, 47, who helped her and sent her to therapy during her teen years, were really concerned about her taking on the character.

"I think me talking about it so candidly is comforting to them," she says. "I wouldn't talk about it – I don't think – if I wasn't feeling better."

Walking the line of reliving her past triggered some emotion for Kravitz in the process.

"It definitely jolted me back in some ways into that world and it was hard to gain the weight back and want to gain the weight back," she says. "I would gain a few pounds and people would be like 'Oh, you gained a few pounds!' and it would trigger whatever that cycle was that wanted to control that."

She adds, "And I think because of that, I dissected it so much for the role and I was really understanding that I needed to break this cycle. Even though it kind of triggered everything back up for me, it allowed me to really confront it and then hopefully let it go forever."

Kravitz, the frontwoman of Lolawolf, says she finally decided to take charge of her life and make a change when her disorder started to affect her voice.

"It messes up your stomach acid and everything like that, and I love to sing and I was realizing the way I had treated my body and all that hatred that I had toward my body for so long was now affecting what I loved about my body, which was singing," she says. "And you can't really get away with treating yourself badly without consequences."

The star says now she wouldn't change a thing about herself.

"I'm coming into a place where I'm trying to love myself more and not let that affect me," she says. "This is the way I'm made and this is it, so I'm going to go with it."

The Road Within is now on Video On Demand and in theaters.