The "Slide Away" songstress, who has been friends with Demi for years, continued: "I was like just so skinny and so pasty and they kept putting me next to this turkey, and I was feeling so bad about myself that I did not wear a bikini for like two years."
Although the former child star looked comfortable in the racy outfit, she said what hurt more than the body-shaming was feeling like she was lying to her fans and leading a double life.
"I felt like having this persona of being the most confident girl on the planet was actually kind of fraud because I was so insecure on the inside that in my personal life I wasn't even wearing bathing suits and shorts."
Overcome with emotion, Demi— who has her own struggles with body dysmorphia and eating disorders— said she wished she could've been a pillar of support for Miley during that difficult period.
"First of all, I'm so sad that you went through that, and I had no idea," the "Anyone" singer, 27, told her. "I wish I could've been there, but I didn't know and I feel like we've gone through times where we're closer and then distant and that's fine, that's what friends do.
"I just wish I could've been there for you."
And the end of their emotionally charged live video, Demi offered some sage words of advice to those who may be struggling with body image.
"I think it’s so important for anybody that has dealt with body image or anything like that, that right now when we’re home with our mirrors and things like that, it’s so important not to get consumed in negative self talk and this goes for anybody, whether you’ve dealt with body image or not, we’re confined into these spaces.
"We’re going to see the same mirrors everyday. We’re going to have some of these same negative thoughts. It’s important not to beat ourselves up over getting nervous, over maybe not you know, eating perfectly, not working out perfectly."
She sober star continued: These are different, very scary times. And we’ve never been through anything like this in our lives so this is all new to everyone and it’s ok. Be gentle with yourself. And just take care of yourself as much as possible."