The pop star said she was a skinny little girl and prayed for curves.
But when she hit puberty she became ashamed of her body - and then tried to hide her assets.
She said: 'God answered that prayer, above and beyond by, like, 100 times, until I was like, 'Please, stop God. I can't see my feet any more. Please, stop!'
'So I started taping them down.
'How long did I tape them down for? Probably until I was about 19.'
Katy, 26, also told how husband Russell Brand, 36, a self-confessed former sex and drug addict has turned his life around.
The I Kissed A Girl star told Rolling Stone magazine: 'He was hardcore. It was drugs, sex and alcohol.
'And he's so fit now. He's changed so much.'
The new issue of Rolling Stone is on newsstands now in the US.
Perry and Brand wed in India in October 2010.