In a new interview with Harper's Bazaar, the endearingly candid Oscar winner has opened up on the pressures she faced to lose weight at the start of her career.
The 23-year-old has revealed that she was told she was "fat" and advised to slim down.
"It was just the kind of s**t that actress have to go through. Somebody told me I was fat, that I was going to get fired if I didn’t lose a certain amount of weight," she recalled.
"They brought in pictures of me where I was basically naked, and told me to use them as motivation for my diet... I was a little girl. I was hurt."
Jennifer defied the critics, and has become the hottest starlet in Hollywood, securing an Academy Award and a leading role in the huge Hunger Games franchise, all by the age of 23.
"It doesn't matter what accolades you get," she said. "I know it will never happen to me again."
Jennifer revealed she has one weakness when she gets on set. "It's normally crisps," she said. "It's not my performance that's motivating me, I want to get the on-set catering!"
In February of this year, Jennifer's meteoric rise was cemented when she received an Oscar for her role in Silver Linings Playbook.
But despite her success on the night, she admitted that one guest – who she refuses to name – told her to "pull it together".
"(The person said) 'Other people are getting up and owning the stage and you sound like a stuttering idiot. Pull it together'," Jennifer recalled.
"And I said, 'I'm not doing it on purpose, I'm uncomfortable and when people get uncomfortable they resort to their s**t. I make awkward jokes and stutter.'
"That was actually a moment when I wanted it to be special. That was not a time I wanted to be the down-home girl. I wanted to be graceful."
Jennifer is currently in the process of filming the third and fourth installment of The Hunger Games alongside Liam Hemsworth. She is currently in a relationship with British actor Nicholas Hoult, who she first met on the set of X-Men: First Class.