Kirstie Alley sits down with Dr. Oz to discuss her very public weight struggles and nothing is off-limits! She speaks candidly about everything from cocaine to body image. Learn what she sees when she looks back on her body over the years and why she regrets wearing a bikini on Oprah. Plus, get the tools that helped her turn her life around for good.

View Part 1 of Kirstie Alley: Confessions of a Yo-Yo Dieter.

Read more about the dangers of yo-yo dieting and how it damages your health.

Watch Kirstie Alley answer your questions from Facebook and Twitter in a web-exclusive video.

Watch as Dr. Oz and Kirstie Alley reveal the damage yo-yo dieting can do to your heart.

For more about Kirstie's weight loss visit