Twenty-four-year-old Lyzzy says she has gained more than 100 pounds since high school. She currently lives at home with her parents who continue to support her and admits she has stolen thousands of dollars from her father and aunt. She turns to Dr. Phil for help, admitting that she’s ready to change her behavior – and her life.

WATCH: Parents Claim Daughter Is ‘Lazy, Manipulative Moocher’ Who Has Stolen Thousands From Family

Dr. Phil tells her that a place to start making changes is by taking better care of her body. “If you don’t value yourself, you’re never going to do better in your life by your own definition,” he says. “Everybody has a personal truth, and we generate the results in our life that we think we deserve. And you not taking care of yourself physically is just a symptom of not valuing yourself overall.”

Dr. Phil introduces Dr. Travis Stork, host of the Emmy Award-winning show The Doctors, and author of the new book, The Lose Your Belly Diet: Change Your Gut, Change Your Life.

“The Lose Your Belly Diet is not really a diet but more of a lifestyle of healthy eating,” Dr. Phil tells Lyzzy.

Dr. Stork adds, “I think a lot of times people think about losing weight strictly from a vanity perspective. And one of the reasons I wrote this book – and I talk about it on The Doctors all the time – is it’s about so much more than that. Carrying too much weight puts you at risk for all the chronic illnesses.”

Dr. Phil continues, “Body image and self-image go up and down together. And your body image is at its absolute worst right now, would you agree?”

“One hundred percent,” Lyzzy says.

Dr. Travis tells her that once she starts changing the foods she eats, she will feel a difference quickly. “This doesn’t have to be the way you live your life if you choose not to,” he says.

WATCH: Secrets From The Lose Your Belly Diet For How To Lose Weight And Return To Health

Lyzzy says she’s ready to make a change. “I can’t do this anymore. I can’t. I’m tired of feeling like absolute garbage,” she says, adding that she started gaining weight when she lost her grandfather. “The day that I lost him, my whole world fell apart. And that’s why I am the way I am.”

“What I came away with is [the diet] gives the person a sense of empowerment and control,” Dr. Phil says. “This is them controlling what they do, what they put in their body and understanding why.”

The Lose Your Belly Diet: Change Your Gut, Change Your Life is available now at TheBookNook.com, and in stores on December 27. It is published by Ghost Mountain Books. Ghost Mountain Books and TheBookNook.com are owned in part by Dr. Phil’s son, Jay McGraw.