Nicole Scherzinger, former Pussycat Doll leader, opened up about the "dark time" she went through with the band. Nicole also called bulimia a "paralyzing disease."

The former X-Factor host may have had bulimia, but she says she was insatiable during her time in The Pussycat Dolls.

Nicole Scherzinger told The Guardian Newspaper "I'm recklessly ambitious. In America, ambition is a good thing - it's hunger, it's drive. I hate it when people use the word negatively."

The singer, 36, called her Pussycat Dolls days her "loneliest time."

"My 20s were fruitful but not enjoyable. Being in The Pussycat Dolls was probably my loneliest time because I was quite insatiable. Nothing was ever good enough and I didn't know how to take a break. My 30s have definitely been more chillaxed," she said.

Scherzinger has been in an on-again, off-again relationship with British Formula One driver Louis Hamilton for six years. She shared a short Instagram video of her singing live with her band getting ready for an appearance British Channel 4's Sunday Brunch on Sunday.

She captioning the rehearsal clip "Rehearsing for @SundayBrunchC4 acoustic set. Live tomorrow at 9:30am #yourlove."

Scherzinger says she has always been very emotional. "My nickname at school was Crybaby. Sometimes I can cry just talking because something means so much. And when I'm really hurting I just sob - a bit like someone is dying. I'm emotionally intense."

She recently told Cosmopolitan magazine "It still is hard, and thinking about it I try not to well up."

The 36-year-old star opened up about her battle with bulimia, saying "It is such a horrible, paralyzing disease and it was such a dark time for me. I didn't think anyone knew in my group or in my family because I hid it that well, I was so ashamed. I knew it wasn't normal or healthy because I was hurting myself through this cycle of disordered eating. It was my drug, my addiction. It's an endless vicious cycle."