Speaking at the Elle Women In Hollywood Awards in LA, Lawrence addressed the large number of allegations of sexual harassment against Harvey Weinstein.
The 27-year-old told the audience that she found the allegations against the movie mogul “harrowing”, before recounting her own story.
She did not identify the project she had been involved with, or name the producers, but in her speech she said she was told to “lose 15lb” in two weeks when she was “much younger and starting out” in the film industry.
Lawrence said: “One girl before me had already been fired for not losing enough weight fast enough. And, during this time, a female producer had me do a nude line-up with about five women who were much, much thinner than me.”
“And we all stood side by side with only paste-ons covering our privates.
“After that degrading and humiliating line-up, the female producer told me I should use the naked photos of myself as inspiration for my diet.”
She continued: “I asked to speak to a producer about the unrealistic diet regime and he responded by telling me he didn’t know why everyone thought I was so fat, he thought I was perfectly ‘f***able’.
“I couldn’t have gotten a producer or a director or a studio head fired. I let myself be treated a certain way because I felt like I had to for my career.”
“I was young and walking that fine line of sticking up for myself without being called difficult, which they did call me, but I believe the word they used was ‘nightmare’.”
Lawrence said she did not want to be a “whistleblower”, and that she did not “want these embarrassing stories talked about in a magazine”.
“I just wanted a career,” she added.
She said it was after being cast as Katniss Everdeen in the hugely popular Hunger Games franchise that she had “the power to say no”.
Lawrence, who was among stars at the annual event including Kristen Stewart, Reese Witherspoon and Jessica Chastain, said that, although she is saddened by the allegations against Weinstein, it has been “oddly unifying” for women in the industry.
Lawrence said that “in a dream world, everyone is treated with the exact same level of respect”.
She had previously condemned Weinstein in a statement to Variety, in which she said she was “deeply disturbed to hear the news about Harvey Weinstein’s behaviour”.
“I worked with Harvey five years ago and I did not experience any form of harassment personally, nor did I know about any of these allegations,” she said, adding that “this kind of abuse is inexcusable and absolutely upsetting”.
A number of actresses have come forward in recent days to accuse Weinstein of sexual harassment, including Gwyneth Paltrow, Angelina Jolie, Cara Delevingne, Rose McGowan and Ashley Judd.
Three women have also alleged that Weinstein had raped them in an article in The New Yorker – claims that have been vehemently denied by Weinstein.
However, the 65-year-old film producer is now facing a number of police probes as its reported he is staying in a rehab centre in Arizona to be treated for sex addiction.