The 'Tragedy' star admitted that a fluctuation in her body weight throughout her career had fuelled her insecurities of being in the spotlight.
Richards told The Sun: "When I was that big [in 2007] nobody would have worked with me. I'd go to meetings and never hear from people again because you are not like they remember you.
"They'd use the phrase, 'She has let herself go'. It was crushing."
The singer revealed that she suffered from a mild eating disorder during her time in Steps as she used to compare herself to the other female band members.
Richards explained: "I had a really small waist but I didn't see that. Faye [Tozer] was much broader on the top, Lisa [Scott-Lee] is smaller with big boobs but all I saw was my bum is huge.
"I didn't really exercise but I never ate. I didn't let on. I'd eat in public to try to make it look like there was no issue."
Steps recently announced plans to release a collection of their hits on an album titled The Ultimate Collection. They will also reform for a documentary on Sky Living.
On the reunion, Richards commented: "I hope that I have the confidence to look at Lisa and Faye and not compare myself anymore."
> Steps' Claire Richards: 'Food is my addiction'
Watch the music video for Steps' hit 'Tragedy' below: