"Well, for me, my revenge body, I started working out during my divorce [from Lamar Odom]," she shared, "but it was more for sanity reasons."
"I was always chubby and just kind of owned it, like, 'I'm big boned, and this is who I am,'" she added. "I always emotionally ate. So, for once, I was like, 'Well, the pints of ice cream never worked for me, so let me try this elliptical,' and the clarity that I got after working out was so great and, as a byproduct, I started losing weight."
Though Kardashian started working out during her split, she says her revenge body isn't targeted towards Odom.
"My revenge is not towards one person," she said, adding that stylists would often refuse to dress her. "It's more for everyone who was so cruel to me and really shunned me."
Gone are the days when the Good American designer would refer to herself as "the fat Kardashian sister." Now, Kardashian says she and her older sisters, Kourtney and Kim, "all compete fitness-wise."
"I always thought that Kourtney was like a little bit of a p-*-*-s-y in the gym so I would never work out with her, because I'm a beast in the gym," she elaborated. "But now we've worked out together and I'm like, 'Kourtney is badass.'"
But when all is said and done, Kardashian really believes that a revenge body is best made for yourself.
"I don't believe that a weight defines you. I don't weigh myself, because I don't care what number I am," she said. "I think to be happy comes from within… There's so many miserable people that are thin and they're hungry!"
Revenge Body With Khloe Kardashian premieres Thursday at 8 p.m. ET/PT on E!
See more on Kardashian's incredible before and after in the video below.