Jessica Simpson lost 100 pounds – three times – with these simple lifestyle changes

Jessica Simpson has lost 100 pounds not once, not twice, but three times.

The entertainer recently posted a picture on Instagram celebrating being back in a bikini after losing 100 pounds following the birth of her third child.

Those of us who have struggled to lose the pregnancy weight — or any weight for that matter — have one question: How did she do it?

The answer may surprise you.

On a recent episode of "The Real," Simpson admitted that it took her three years to lose the weight this time, according to Entertainment Tonight. The 41-year-old mother of three has been focused on making small lifestyle changes to safely lose weight after she welcomed daughter Birdie Mae in March 2019.

“I call it determined patience. I believe in setting small goals for yourself, because in my life and how I’ve done it, there’s easy ways to throw in the towel and just feel like it’s impossible," she said. "So, the small goals for me are what helped me achieve the main goal."

Related: Experts told TODAY how walking can help with weight loss and shared some quick tips on how to make your workouts even more effective.

Her longtime trainer, Harley Pasternak, said getting her steps in every day — at least 14,000 of them, to be exact — was key to helping Simpson shed the weight. Pasternak said Simpson started out by walking 6,000 steps per day.

"It had to be more than just getting back from her baby weight, but how do I keep whatever I am doing now forever. That's why we are not a big fan of doing any extreme diet or radical forms of exercise," he told E! News in an exclusive interview.

Simpson eventually worked her way up to at least 14,000 steps per day. She first showed off her results in September 2019 and appeared strong and happy keeping up the routine in an Instagram post in May of the next year.

"Woke up before all 3 kiddos to get my steps in and spend time with me, myself, and I," she wrote. "Move move move for your own mental health."

Focusing on her mental health was clearly an important part of Simpson's weight-loss journey. Last year, she told TODAY that she had thrown out her scale and makes a point of not weighing herself regularly. “I have no idea how much I weigh. I just want to feel good and be able to zip my pants up. If I don’t, I have another size. I have every size,” she said. “I’ve really tried my hardest to not let that define me.”

Related: Valerie Bertinelli is revealing how she avoids worrying about her weight.

Simpson also focused on eating three healthy, protein-packed meals a day and two snacks, such as almonds. Instead of cheat days, she would have several cheat meals throughout the week, Pasternak said, that way she didn't feel deprived of her favorite foods.

Pasternak advised Simpson on one overlooked component of weight loss: getting enough sleep. He said the fashion mogul aimed for seven hours a night.

"So many people undervalue the importance of sleep in weight loss and weight management," he said.