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OTRC: Kelly Osbourne loses 50 lbs, shows off bikini body

Kelly Osbourne appears on the cover of Shape magazine's December 2010 issue. / Kelly Osbourne arrives for the MTV Europe Music Awards in Edinburgh, Scotland, Thursday, Nov. 6, 2003. (Shape AP / Sang Tan)

Kelly Osbourne shows off her new bikini body on the cover of Shape magazine's December issue and the former reality star, who lost 50 pounds over the past year and is now a size 2, says the photo is the ultimate revenge on every media outlet that had called her fat.

Osbourne, 26, appeared heftier when she starred with her rocker-father Ozzy in the reality series "The Osbournes" several years ago.

"To be called fat and ugly your whole, entire life by everybody in the media ? to now be on the cover of Shape magazine, it's like the best '(expletive) you' I could have ever had in my entire life," Osbourne told Shape magazine in a video interview.

She said that when she began getting into shape, she initially she could barely walk on the treadmill and could not do one sit-up, because it made her feel sick. She says she can now do 100 of them and likes lifting weights and doing push-ups. She detests squats.

"You've got to be dedicated to what you're doing and you've got to find a way to make it fun," Osbourne said. "If it's not fun, no one wants to do it and to get in the gym every day when you already don't like yourself, it's really hard."

"I know how hard it is to get into the routine of it, so I've done things like get cute gym outfits and purposely wear make-up at the gym because when you look at yourself in the mirror, if you don't like what you see, you're not going to want to keep doing it," she added

Osbourne credits "Dancing With the Stars", the ABC ballroom dancing show she participated in last year, as the main reason for her weight loss.

"If it wasn't for you, I would be standing here, Mr. Van Amstel," Osbourne told OnTheRedCarpet.com earlier this month, referring to her former "Dancing With the Stars" partner, pro-dancer Louis Van Amstel. "He changed my life as well as the show did. He got me eating right. He got me working out. He's a huge part of the reason that I changed."

Osbourne, who placed third on "Dancing With the Stars" in 2009, has said she was moved to tears when she saw the first photo from her Shape photoshoot.

Osbourne posed nearly naked and covered in gold body paint for a photoshoot spoofing Shirley Eaton's role in the James Bond film "Goldfinger" to promote the UK television network Sky's new HD channel package.

Osbourne also praised current "Dancing With the Stars" contestant Bristol Palin, the daughter of former governor of Alaska Sarah Palin who on Tuesday became one of three remaining couples left on the show.

"People better vote for her because she's what the show is all about," Osbourne had told OnTheRedCarpet.com. "She's had no experience dancing before, let alone performing experience and she's just getting better and better every week and I applaud her."

Check out behind-the-scenes footage of Kelly Osbourne's Shape magazine photoshoot: