NBC's The Biggest Loser has produced some truly incredible transformations over its 15 seasons. Many contestants lost half their body weight -- or more, as in the case of season 15 winner Rachel Frederickson. Take a look back at the some of the show's most jaw-dropping makeovers.
Matt Hoover - Season 2 - Before
At the start of the show's second season, former wrestling coach Hoover, now 33, tipped the scales at 339 pounds.
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