Kelly Osbourne Weight Loss Transformation: Star Reveals 'I Never Thought I’d Be A Skinny Girl'

Kelly Osbourne has made a 180-degree turn since her days on “The Osbournes,” both in her career and her new healthy outlook on life. In a new interview with In Touch Weekly the star revealed how she lost 50 pounds and kept it off, and why she “never thought she’d be that kind of girl.”

Osbourne, who previously battled an addiction to painkillers and made several trips to rehab before kicking the habit, made a very public physical transformation after appearing on “Dancing With The Stars.” The daughter of Black Sabbath rocker Ozzy Osbourne credited her dance partner, Louis Van Amstel, with instructing her on how to eat healthy, saying it gave her so much more energy on the show and kick-started her weight loss.

“People think I lost weight and then got happy, but that's not how it works. You have to get happy first,” Kelly told In Touch, adding that she enjoys being active.

“[Working out] is something I really enjoy doing. I never thought I’d be that kind of girl,” she said. “I do up to half an hour of cardio, and I also do circuit training, yoga or Pilates — I mix it up.”

In an interview with Shape in December of 2011, Osbourne told the publication that her diet had been terrible before going on the reality competition show, and she often suffered from fatigue. "I'd fill up on French fries and pizza all day and wonder why I wasn't losing weight. In the very beginning [of “Dancing with the Stars,”] I kept getting sick during rehearsals because I was eating such terrible, fatty food and feeling so exhausted.

"I would look at myself and think, 'Ugh!' I was miserable. To get to the gym — when you already don't like yourself — is really hard. So I had to make it fun. I started wearing cute outfits and putting on a little bit of makeup. And as vain as it sounds, it really helped me because eventually I stopped hating the way I looked.”

Osbourne did admit, however, that one of her keys to dieting is allowing herself some indulgences. “I do cheat,” she said. “I have one cheat day a week where I eat whatever the f--- I want ... never deprive yourself of anything, because then you get angry about it,” she said, adding, “People who are hungry are miserable.”

Aside from her “cheat day,” Osbourne said she tries to be very careful about what she eats. “For breakfast, I will eat either cereal or a little omelet thingy made with egg whites, mushrooms and spinach. Lunch is usually a salad or a turkey burger. And then for dinner, I’ll have brown rice with vegetables and some kind of meat.”

In her interview last year with Shape, the “Fashion Police” star blamed the weight shaming she received at the hands of the media on self-esteem issues and substance abuse.

"I was called fat and ugly in the press almost my entire life," said Osbourne. "I understand that being judged by others comes with the territory, but it broke my heart and ruined my self-esteem. It sets you up to hate yourself in a huge way. I was so angry about the things people said about me. I truly believe it's the main reason I turned to Vicodin and ended up in rehab three times. I just hated myself."