'I had really bad back problems and was a little bit thicker,' the 26-year-old singer explained.
But the chart topper learned to love her shape, she told Harpers Bazaar. 'Then I grew up and lost the baby fat and said, 'Hey, this isn't all that bad.''
Perry, who recently wed British comedian Russell Brand in a lavish ceremony in India, went on to reflect about her image.
'I'm kind of a good girl, and I'm not. I'm a good girl because I really believe in love, integrity, and respect. I'm a bad girl because I like to tease.
'I know that I have sex appeal in my deck of cards. But I like to get people thinking. That's what the stories in my music do.'