Author James Frey confessed to Oprah Winfrey on Thursday that he made up details about every character in his memoir ``A Million Little Pieces'' and the talk show host apologized to her viewers, saying she felt ``duped.''

``I have been really embarrassed by this,'' said Winfrey, whose praise for Frey's book in September helped make it the top-selling book on nonfiction lists in the United States last year.

``I really feel duped,'' she told Frey on her television show. She said he had betrayed millions of viewers.

At one point early in the interview Frey said he still viewed the work as a memoir, not a novel. By the show's end Winfrey made him admit he lied.

``This hasn't been a great day for me,'' he said. ``I feel like I came here and I have been honest with you. I have, you know, essentially admitted to ...''

``Lying,'' Winfrey interrupted.

``To lying,'' he said. ``It's not an easy thing to do in front of an audience full of people and a lot of others watching on TV. ... If I come out of this experience with anything it's being a better person and learning from my mistakes and making sure I don't repeat them.''