The 80-year-old E! Fashion Police host said she finds the actress "terrific," but argued that Dunham's body-positive message is, in fact, a harmful one.
"[Lena Dunham], you are sending a message out to people saying, 'It's okay! Stay fat! Get diabetes. Everybody die! Lose your fingers,'" Rivers asserted.
"I love that she's funny and love that she's done well," she continued. "But don't let them laugh at you physically. If you look the way you look, Lena, and that's fine and you're funny, don't say it's okay that other girls can look like this. Try to look better."
The Fashion Police host also said she found Dunham's cover for Vogue hypocritical. Rivers seemed to imply that the actress should not have done the cover if she feels strongly about body non-conformity, and that her anger over the $10,000 bounty for her un-retouched photos was invalid. "I didn't know it was her," Rivers said. "I'm on fire over hypocrisy."
Stern made attempts to defend Dunham during the interview, in spite of his own previous criticism of the actress's weight. The radio host had referred to her as "a little fat girl who kind of looks like Jonah Hill" in January 2013. He later apologized and expressed admiration for Dunham's talent.
Notable deaths of 2014 [PHOTOS]