In spring 2009, Britney Spears' ex-husband and father to her two sons Kevin Federline a.k.a. K-Fed shocked the world in a new rotund physique.  The 31 year-old ex-rapper had gained an estimated 85-100 pounds in the wake of his divorce from Spears.

But the aspiring rapper has gotten his act together and lost 50 pounds as a contestant on the next season of VH1's Celebrity Fit Club, airing in January.

Shar Jackson, Federline's ex-girlfriend and a fellow Fit Club contestant, recently told Usmagazine.com, "I think everybody will be very, very shocked to see the end results," noting that they both survived a "very painful" boot camp on the show.

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