Nicole Scherzinger. Picture: Bang Showbiz

Nicole Scherzinger says her battle with bulimia stole all of her "happiness, confidence and memories".

The 39-year-old singer had always been critical of her appearance but her eating disorder was at its worst during her time in The Pussycat Dolls.

She told the October issue of Britain's Cosmopolitan magazine: "It was very imprisoning and it stole all of my happiness, confidence and memories. A big part of that was during The Pussycat Dolls. I have a lot of fans and I never wanted to come out about it, because I was ashamed. But once I finally did come out about it, I realised how many people it had helped.

"When I got The Pussycat Dolls, it really amplified that because it had so much to do with showing your body off... But you should embrace and accept yourself more. Don't be so hard on yourself, and love your curves."

Even as a teenager, Nicole struggled with how she felt about her appearance and took up running to get thinner thighs.

She said: "I'm more accepting of my body now. I was always very critical of myself from a young age, and when I was 14, I started running. I would go outside in the middle of the night and run, because I thought I had to be thinner and that my thighs should look a certain way."

These days Nicole keeps in shape, and clears her head, by going to the gym.

She said: "Every woman has good and bad days. Mrs O [Sharon Osborne] and I were joking the other day that sometimes we wake up in a puddle of cookies and crisps! But what really helps me is working out. Even if it's not for very long, [I love] to get a sweat on to keep me focused and positive."