Los Angeles - Actress Jennifer Aniston says she was grateful for her body after playing a role of pill-popper and chronic pain sufferer in her upcoming film 'Cake'.

The 45-year-old actress studied 'pretty much every single part of the body' that was hurt or injured, including the back, the leg, and the neck. She stopped her workout routine for two months to prepare for her role in the movie, and it did take a toll on her body.

"It really was interesting when you stop working out how you just ... My serotonin levels went down. My stamina was shot. I was cranky. I was irritable. I found myself short. I was hungry like crazy," she said.

Fearing that her body would manifest any of the cricks, pinches, lower back pain, or any other pain for good, she maintained some form of body work that would prevent them.

"There would be times when I would have to do a take over because I knew I moved too easily, but what's odd is that after about two weeks of walking and taking on a physical state, that starts to become sort of your natural state of being and moving."

'Cake' is about a bitter woman, Claire Simmons, who suffers from chronic pain. She is infatuated by the suicide of another woman from her chronic-pain support group, Nina, and as Simmons pursues the story behind Nina's death, she builds a relationship with Nina's husband while struggling against her personal tragedy.

'Cake', also starring William H Macy, Felicity Huffman, and Mexican actress Adriana Barraza, will release on January 23. PTI