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Molly Sims is opening up about what it was like to be one of the most sought after models in the world in the '90s -- and it was pretty famishing.

"I didn't eat sometimes for a couple of days," the supermodel-turned-actress told the Huffington Post. "And I used to walk 14 miles a day."

The idea of maintaining a perceived perfect figure was exhausting.

"It was very difficult to stay the weight you're supposed to be," she said, while promoting her book "The Everyday Supermodel." "I am blessed genetically but I still had to work hard to get to the weight they wanted me to be at."

She's proud now of many of her old modeling shots, but she's also shocked to see some of them.

"You never think you look good at the moment but then you look at the picture five years later you like it," she said. As she looked at photo of herself in which she appeared very thin, she said, "At that time I thought I was so heavy."

Nowadays married with two children, her focus is more on her family, but she still works out. But, her life so hectic that she has to physically schedule exercising and write it in her calendar. In fact, she says she's very OCD and very organized about her life.

"It's difficult but now as a mother of two that work-life balance is always hard," Sims says. "It's a juggle. I do want to be the best mom I can be but I also want to do the best work that I can do. So, it's my own little ambition, kind of a life pole that I keep trying to climb. But there's pressure on that, you know."