"If I could have anyone's body, I'd love to be a supermodel. I'd love to be skinny for the day," the 31-year-old said.
Kardashian says accepting yourself the way you are is a gradual process.
"It's a process. You have to learn to accept it. You have to learn to like what you see in the mirror, but there are definitely times when I don't. I'm built a certain way and you just can't change that," she said.
"In Hollywood, people are used to stick-skinny women, and that's never going to be me. Growing up, I'd look at those skinny models and feel like I looked different," she added.
She has been in news after breaking up her 72 days marriage with basketball player Kris Humphries. She is currently dating musician Kanye West.