E! host Giuliana Rancic says she knows she's too thin

E! host Giuliana Rancic is speaking out about her weight after months of criticism that she's gotten too thin.

Rancic tells People Magazine that rumors about eating disorders and a possible new bout of cancer compelled her to go on the record about what's really going on.

Rancic, who battled breast cancer in 2011 and underwent a double-mastectomy, told People she's lost a lot of weight because of the cancer drugs she's had to take.

"I started noticing that I was eating a lot, but not gaining weight at all," Rancic, 40, told the magazine. "I was concerned."

Rancic said that the criticism has been hurtful.

"I'm sorry that some people think I'm disgustingly skinny, as they put it, but there's nothing I can do," she said. "I look in the mirror and it's hard for me," she said. "I am really thin. I want to look fit and beautiful and sexy, and I can't."

Rancic is married to Bill Rancic, the winner of the first season of NBC's The Apprentice. The couple has a 2-and-a-half-year-old son, Duke, who was born via surrogate.

Recently, Rancic came under fire for comments made on an episode of E!'s Fashion Police about entertainer Zendaya's Oscars look. Rancic issued a taped apology and co-hosts Kelly Osbourne and Kathy Griffin left the show following the incident.

Rancic's memoir, "Going Off Script," hits shelves April 7. The book follows the 2010 release of the couples advice book she wrote with husband Bill, "I Do, Now What? Secrets, Stores and Advice from a Madly-in-Love Couple."