When the 27-year-old was compared to an uncooked chicken and a 'turkey', she lost all her self-confidence. At the time, we can remember Miley being carefree and unapologetic in what she wore and how she acted.
She admitted: "I basically went through two or three years where I wouldn't wear shorts. I stopped wearing skirts on stage, all this s**t, because after the VMAs and I had on my cute new bodysuit, everyone started comparing me to a turkey.
"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."
Miley added that the world's reaction "really affected her personal life" following her performance with Robin Thicke.
"No one thought that that would've ever made me feel some type of way. It was just really really hurtful to be so body-shamed like that. And it really affected me in my personal life."
Following the event, Miley went on to say that she felt like a "fraud" because she was so insecure.
"What was so hard about it was my brand has always been about being so unapologetically myself and being confident, and the worst thing that I would feel like I would be to my fans would be lying or a fraud.
"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."
She added: "And when I was wearing like my little leotards and things, I had on f***ing four pairs of tights because I was so insecure."
Demi, who has been close with Miley since their Disney days together, has been open about her body-image struggles. She agreed that she also used to wear multiple layers of tights to feel more comfortable.
"I kind of made a vow to myself that when I get older I just wanna represent what I didn't have, and I want to be that for somebody," Demi added.
"I've talked about my struggles with food and stuff, and yeah, I'm glad that I did because it's brought me and my fans closer. It, I feel like, helped young people learn to accept their bodies when it starts to change."
If you would like to talk to someone about an eating disorder, you can call The Butterfly Foundation on 1800 334 673.