"I'm very insecure about my butt. I suppose I tend to put on weight there. I'm just happy it's behind me and I never have to look at it," Hunter told Britain's Mirror Thursday.
Hunter, who has two children with ex-husband, rocker Rod Stewart, to whom she was married from 1990 to 1999, said she decided to pose for Playboy after being asked for years.
"I was first asked when I was 18 and I kept saying, 'No, no, no.' Then I got to a stage where I felt comfortable about doing it. I was pleased with the result. Playboy is a part of history and I wanted to be a part of that. It's a notch on your belt in some ways," she said.