The 26-year-old singer announced she was checking herself into rehab for an eating disorder. It's no secret Ke$ha has definitely been looking slimmer. So what caused her extreme slim down? Sources say Ke$ha is telling pals that record producer Dr. Luke is the reason she checked herself into rehab, claiming he bashes her weight and has even called her a "big fat refrigerator!" In a statement on Facebook she explained, "I'm a crusader for being yourself and loving yourself but I've found it hard to practice. I'l be unavailable for the next 30 days, seeking treatment for my eating disorder, to learn to love myself again, exactly as I am."