Kevin Federline has made his debut on the Celebrity Fit Club and he is opening up about how it felt to be called ‘K-Fat’. He says he discovered he was fat when he was on the road and saw some pictures of him published. When asked how he felt about being called ‘K-Fat’, he admitted that it was hurtful and that even his mom told him that she was worried about his ‘health’ due to his weight gain. He went on to say that his relationship with both exes, Britney and Shar Jackson, is great but says that his woes with Britney Spears was also partially to blame for his weight gain. As far as losing the weight he said “It feels great, it really does!”.