Transcript from the Oprah Winfrey Show

In 2002, Kathrine Lee showed off her 175-pound weight loss on Oprah's stage. Proud of her hard work, Kathrine thought her weight struggles were gone for good. "I would have sworn on a Bible that I had it together," she says. "I thought: 'There's no way I will ever go back to being the way I was before. Ever."

Kathrine had kept the weight off for seven years, but after she met her future husband, she says the pounds began creeping back. "When love came in my life again, I got on birth control when we got married and gained 20 pounds. I had never had a chemical weight gain," she says. "Then I got off birth control and got pregnant, and then I gained more weight."

By 2009, Kathrine had gained back 150 pounds. "I knew things were out of control with the first 20 pounds, and then I said, 'Forget the whole thing,'" she says. "It became a complete self-sabotage at that point. I began to hide. I began to feel I wasn't worthy anymore."

Kathrine says regaining the weight was harder than being overweight in the first place. "I felt like a fraud," she says. "I was in the industry. I was teaching on the subject, and now I was doing exactly what I knew not to do."

Looking back, Kathrine says her biggest mistake was not losing the weight for herself. "I made it about everybody else. I was either doing it for them or to get a reaction from them," she says. "The obsession or the running to food got replaced with people's attention. It got replaced with the motivation of other people saying great job."

Kathrine says she was even convinced her weight would make her husband leave. "I was still in the cycle of 'only if I'm thin am I lovable,'" she says. "'Only if I'm thin am I okay.'"

Though her husband's love never wavered, Kathrine's self-respect had all but disappeared. "I'd wake up in the morning and I thought, 'I hate myself,'" she says. "And of course, guilt would come on because I have such a great life and great family."

Finally, at 300 pounds, Kathrine had an aha! moment. After reading Geneen Roth's book Women, Food and God, Kathrine learned losing weight is not about punishing or depriving yourself—it's about embracing yourself. "Kindness is actually what heals," she says.

Kathrine made the life-changing decision to love herself—no matter her weight. Since then, she's lost 100 pounds. "I was excited when I went from a 28 to a 26. I felt valuable because I know who I am. I know that I'm so much more than my weight. My value is not fluctuating with my size," she says. "These hips are what birthed my children. These hips are what take me from here to there to love people and care about people and love right where I was, love who I was."

Kathrine has stopped hiding and even returned to teaching. "I'd look out [at my class] and think, 'Why do they want to learn from me?' And then I'd say: 'Because you're smart. Because you're kind. Because you're authentic. Because you have wisdom,'" she says. "And they felt the same way about me—and I was 300 pounds at that time."

When she walked across Oprah's stage in 2002, Kathrine said, "I like me now." Looking back, Kathrine can now proclaim something her former self never could. "I couldn't say, 'I love me now.' ... The 'now' [was] the fact that it was now that I had lost the weight," she says. "Now it's just: 'I love me. I'm valuable.'"