Rapp starred in the musical aged 19 as “queen bee” Regina George (played by Rachel McAdams in the original 2004 comedy).
During a new interview with The Guardian, Rapp said that her eating disorder at the time was exacerbated by production staffers who “would say some vile f***ing things to me about my body”.
She said her parents even flew to New York to try and convince her to quit the show over fears for her mental health.
“Eating disorders don’t just go away and like, you’re healed, like: ‘Sorry, I can eat again, ha ha!’ It’s a lifelong thing,” she said.
“There are battles with addiction and whatever everywhere. I still struggle with it, but at least my parents know that I’ve been taken out of environments that were really harmful to my sickness, which is awesome and a huge win. They worry like hell, but they’re chilling, I guess.”
Rapp has been open in the past about her struggles with mental health and struggling to come out as bisexual.
She recently admitted to “hating” herself for months after being cast as a gay character on Max’s The Sex Lives of College Girls.
“I had a boyfriend at the time, and I was being very homophobic to myself. I was like, I don’t deserve to be doing this; I’m not gay enough,” she told The Cut.
Last month, it was announced that Rapp would be taking on a smaller role in the third season of The Sex Lives of College Girls before leaving completely, in order to focus more on releasing music.
Thanking series creators Mindy Kaling and Justin Noble for believing in her, Rapp shared of her departure: “A lot of queer work gets belittled – but playing Leighton has changed my life. I love who I am 10x more than I did before knowing her. I hope she gave y’all a little bit of that too.”
Earlier this week, Rapp was being interviewed by Drew Barrymore in New York when a man appeared to rush the stage. Rapp was seen wrapping her arm around Barrymore, whom the man had addressed, and rushing her off stage.
When they returned, Barrymore told Rapp: “Well, I got a new definition of your sexiness, it’s that level of protectiveness. That went full bodyguard!”
She joked: “You are my Kevin Costner!”
For anyone struggling with the issues raised in this article, eating disorder charity Beat’s helpline is available 365 days a year on 0808 801 0677. NCFED offers information, resources and counselling for those suffering from eating disorders, as well as their support networks. Visit eating-disorders.org.uk or call 0845 838 2040