Brooke Shields claims her mother used to call her fat as a young model

At age 53, Brooke Shields is slipping into her Calvins again, but her return to the modeling world was far from easy.

The former child star, who originally stirred headlines for playing a 12-year-old prostitute in 1978’s “Pretty Baby,” would go on to become the youngest model to appear on the cover of US Vogue.

Shields appeared in her first ad for Calvin Klein jeans in 1980 at 15. She famously said, “What gets between me and my Calvins? Nothing.” The image became one of the most iconic ads in fashion history.

The actress would go on to maintain a steady career in Hollywood. And in 2017, Calvin Klein CEO Steve Shiffman announced plans to work with Shields again 37 years after the controversial ad caused a sensation.

“I modeled swimwear when I was 15, and even then I didn’t think I had a swimsuit body,” Shields admitted to net-a-porter Friday. “I was a cover girl, not a supermodel. I was ‘neck up’ – the face, the eyebrows – and I was always described as ‘athletic’; ‘not rail-thin’; ‘not a runway model.’ Those messages they seep into your consciousness.”

Shields confessed that at a young age she struggled to accept her body because her own mother, also her manager, said harsh words to her.

“My mother would get drunk and say: ‘Why don’t you move your fat ass?’ So, I’ve always believed I had a fat ass,” said Shields.

Teri Shields passed away in 2012 at age 79 after a long battle with alcoholism.

But the actress, a mother of two, has learned to embrace her figure over the years despite spending a life in front of cameras.

“We shouldn’t just see 15-year-old bodies,” she explained. “I don’t want a 15-year-old body. I don’t want to look like a little boy. There is a huge market for women who have money and don’t want to look prepubescent, but don’t want to look like old ladies either.”

Shields, who had knee surgery in April, also revealed she’s hired a personal trainer to stay as fit as possible.

“I hate trainers. I hate gyms,” she said. “But I worked so hard, so consistently, that I’ve now got some [fashion] campaigns, at 53, that I might not have otherwise.”

And her husband of 17 years, screenwriter Chris Henchy, has been supportive throughout her journey.

“… He really celebrated my womanliness and my body,” said Shields. “And I needed a man to celebrate me.”

And as for posing again? Shields said she’s feeling much more confident for the ongoing campaign.

“I really prepared,” she explained. “I knew that if I didn’t look my best, I’d be embarrassed and mad at myself. I stopped drinking beer and wine, and I worked out three times a week. I was the best version of myself.”

She also joked, “I was also hungry.”

Back in 2014, Shields wrote about her complicated relationship with dominating matriarch Teri in the memoir “There Was a Little Girl.”

“Once my mother passed away, I thought that it was the appropriate time for me to tell my version of our story,” she told Fox News at the time.

Shields added that she has since gained a greater understanding of her mother’s actions while writing and researching.

“I knew how she acted, I could piece together information, but she rarely told me how she really felt about things,” said Shields. “And I think that was sort of sad and surprising to me to realize, in a way, how little I knew about the pain my mother was feeling.”

Shields also told Fox News in 2015 she can still fit into her famous jeans.

“It’s not pretty, but if I lie down, and I suck in, I can get ‘em zipped up,” she said. “I did it once, and I proved something to myself. I’m not sure what. And then I folded them back, put them in the archives and then gave the other pair to the Met.”

It also takes plenty of no-nonsense work to stay in Calvin Klein-ready shape.

“I have to work at it,” she said. “It doesn’t come easily to fit into anything. I spin and I do yoga and, you know, if I limit myself with alcohol I usually lose weight. And if I stop eating pasta and bread I usually lose weight.”