Mila Kunis restricted her eating habits immensely when starring in the psychological thriller “Black Swan.”

“My prep was a lot of dancing and very little eating — which I know you’re not supposed to say, but it’s the truth,” the actress told Vogue in a joint interview with her co-star in the 2010 film, Natalie Portman.

“I drank a lot of broth and danced for 12 hours a day,” she added in the piece published Friday.

Kunis, now 42, added that she and Portman — who played professional ballerinas — only expected to have three months to prepare for their dance intensive roles.

However, after producers lost some financing, the project “got extended to six months while Darren [Aronofsky, the film’s director] tried to find money.”

“It sucked for Darren, but Nat and I were so happy because we had three extra months to dance,” the “That ’70s Show” alum said.

Kunis — whose alter-ego character Lily is billed as the “Black Swan” — also shared some of the brutal physical effects of the ballet sequences.

“We would shoot those dancing scenes for hours, and I had bruises all over my ribs just from being lifted over and over again,” she recalled.

“I also dislocated my shoulder pretty early in the production and thought I was completely screwed, but Darren sent me to an acupuncturist and I somehow came out totally fine.”

Portman, who played lead Nina Sayers, said she learned a lot about the ballet industry throughout filming.

“One of the most surprising side effects of doing the physical training was that I ended up spending a year talking extensively to my trainer, who was a former New York City Ballet dancer and told me hours of stories that gave so much color and insight into that world,” the Oscar winner said.

“It was like doing investigative journalism, but I was just gossiping with her while doing pliés.”

Kunis first spoke out about her dramatic 20-pound weight loss for the film back in 2012. At the time, she told Harper’s Bazaar that her physique “has never been the same.”

“My shape is different,” the “Ted” star said. “When I got down to 95 pounds, I was muscles, like a little brick house, but skin and bones. When I gained it back, it went to completely different areas.”

Kunis further explained that “all the weight that left [her] chest went to [her] side hip, [her] stomach.”

When asked if she would take on another role that required her to lose weight, the “Friends With Benefits” star noted, “I’m not going to say I’d look forward to it, but if an offer came along, I’d do it.”