Once upon a time, Molly Sims was a supermodel in the same ranks of Giselle and Adriana Lima. But looking back, she realizes she went to some extremes in order to maintain her size zero figure."I would walk 14 miles a day," Sims recently told HuffPost Live . "It was very difficult to stay the weight that you were supposed to stay." She also added that — while she's genetically blessed in some ways — she also struggled to stay rail thin. "I didn't eat sometimes for a couple of days."She also admitted that even when she was at her smallest size, she never felt like it was enough. "You never think you look good at the moment. But then you see that picture five years later and you're like, 'Damn girl I look good,'" she explained. "At that time, I thought I was so heavy."Part of that most likely had to do with the constant feedback Sims was receiving on her looks. "I was always known as the muscular girl," remembers the model, who also once approached a plastic surgeon about making her calves smaller. "That's the obsessiveness that we can get into," she added, "never feeling that you're good enough."These days, the 42-year-old mother of two says that working her way into a single digit size is no longer top of mind. "What I look like, it doesn't have as much weight," she explained. "Now that I have a husband and a family and I have kids, I'm not consumed with trying to get into the size 2. Who gives a shit if I'm in a size 6?""What we all learn is that beauty isn't a size 2, it's not a size 4, it's not a size 12," Sims went on. "It's how you feel." Listen to the interview in its entirety — including her thoughts on achieving healthier body image — below.