Super skinny Nicole Richie has been admitted to a medical facility to determine why she is unable to gain weight.

The Simple Life star's publicist issued a statement Thursday stressing that Richie does not have an eating disorder.

"She is working with a team of doctors and specialists whose focus is nutrition," said Nicole Perna. "It is important to Nicole that she achieve this goal in a healthy way."

Richie, 25, has been dogged by speculation about her weight loss. In an interview with Vanity Fair in June, the daughter of singer Lionel Richie admitted she is too thin.

"I really do need to do something about it," she told the magazine.

"I'm not happy with the way I look right now."

Last month, Richie denied a report by CNN claiming she was in treatment for an eating disorder.

"I did not check myself into an eating disorder rehab," she said, in a statement. "I do not have an eating disorder, and I don't know how many times I have to say it."

On the Tyra Banks Show, Richie said she was not suffering from anorexia. "Absolutely not," she told Banks.