"Biggest Loser" fan-favorite Tara Costa is being sued after she allegedly gained too much weight. According to the Daily Mail, her sponsor FC Online Marketing has filed a lawsuit against Costa for breach of contract. The company said Costa failed to stay under a certain weight specified in her contract.

 According to TMZ, the company wanted Costa to represent them in the media after her appearance on the hit show. Part of contract included that she must maintain a certain weight as made public appearances and posed for photo shoots.

The company said that in 2011, the 23-year-old gained "far too much weight" and they could no longer use her as an ambassador. According to the Daily Mail, one of the appearances included a guest spot on the "Biggest Loser" where she weighed in at 161 pounds, 22 pounds heavier than in 2009 after she lost all the weight on the show. The company claims they gave Costa $45,000 to represent them but is asking for "an unspecified amount in damages," the Daily Mail reports.

In a statement to Newsday, Michael Parella, the company's chief executive said: "We hired Tara Costa in 2011 to be a spokesperson. She came on at a certain weight. We had a fitness clause. She was in material breach after she gained, in my opinion, about 45 pounds. She was supposed to visit 15 of our franchise locations, but we weren't able to send her anywhere because she gained a lot of weight."

Costa tweeted a response to a fan saying the lawsuit and time period is at a time when she felt like she was "the most fit" referring to when she completed in the Ironman World Championship in Kona back in 2011. Despite the allegations, Costa still has a strong fan based who tweeted for the reality star to keep her head up. She thanked her followers replying that it's hard to get her down. She also posted photos saying that she was happy with her weight loss so far.

Costa shot to fame after competing on the show "Biggest Loser: Couples 2" where she lost 155 pounds.