Transcript for Sailor Brinkley-Cook reveals her struggle with body dysmorphia
Looking forward to thafrjts sailor brinkley-cook, the 21-year-old daughter of model Christie Brinkley, she is opening up about her struggle with body image that came with the spotlight. The pressures of being compared to her mom. And what she described as eating order tendencies and Deborah Roberts joins us with her message for other women. Good morning, Deborah. Reporter: Good morning, Amy. Yeah, she offered those revelations on social media where most aren't honest with our posts. But sailor brinkley-cook decided to actually get real online and reveal a difficult truth, that she's 1 of 20 million young American women struggling with body image and eating disorders. Is a wish Reporter: She waltzed into stardom on "Dancing with the stars." Will come true Reporter: Sailor brinkley-cook taking the place of her mom model Christie Brinkley after she was sidelined with an injury. It's sailor brinkley-cook. Reporter: Life seemed so rosy for sailor, a budding model herself. But behind the camera she says not everything was so picture perfect. I have this awful feeling that if I'm not skinny, I'm not worth being celebrated. Reporter: The 21-year-old revealing her struggle with body image on Instagram writing that she was getting mad that I'm not as skinny as I once was. The body dysmorphia and left over eating disorder tendencies have been coming in strong. I've been just having these moments of looking in the mirror and being disgusted with myself for the tiniest little things like -- Reporter: A stunning shift from the effervescent teen model I sat down with seven years ago. Secretly this smiling girl was dealing with an eating disorder. You seemed to be brimming with confidence but there was something else going on inside you at the time that I didn't even see. I remember looking at those photos and feeling so happy with myself because I had a thigh gap in the photos of us walking through the garden. Reporter: As a child she says it wasn't easy stepping into the media glare with comparisons to her near mirror image mom. I grew up a little bit overweight and I felt the weight of my overweightness on me constantly from people teasing me from people looking at me differently. Also being compared to your mother all the time. It's just crazy how that can really like just shut down your self-esteem because you think -- you want to grow up thinking you're your own person. You and your mom are so close. How much did she know about your My mom didn't fully know the pain that I was going through when I was at my worst. Reporter: Her advice to other young women battling similar demons. Life is too short to not celebrate your body. It took courage for sailor to open up but said she did so to help other young women embrace and love themselves with any imperfections, something she's learned to do with the support of her mom and others in her life. Amy. All right, thank you so much, Deborah, for bringing her story.
This transcript has been automatically generated and may not be 100% accurate.