Casey Kasem's Daughter -- Weight Loss Program Made Me Fatter and Nearly Killed Me

Casey Kasem's daughter -- an aspiring singer -- claims her weight problem went from bad to DEADLY ... all thanks to a quack wellness center that plied her with crappy weight loss meds ... and now she's suing.

Liberty Kasem filed the lawsuit against Dr. Edgar Guess of Beverly Hills Wellness Center, claiming she sought out his medical advice on losing weight while prepping for a music video shoot in 2012.

Kasem claims Guess gave her a treatment plan that included a new diet, vitamins, meds, and supplements. Six months later Kasem says she began to experience serious health problems.

One day, Kasem says she began to sweat profusely and vomit -- and exhibited other symptoms that caused her to fear for her life. Worst of all, she claims she hadn't lost any weight ... in fact, she'd GAINED.

As a result of the sudden health problems, Kasem claims she had to be hospitalized. She's suing Guess for medical bills, lost wages, and other unspecified damages.