The `Firework` singer prayed for big breasts when she was younger, but admits she didn`t "understand" her body and tried to hide what have since become her two most famous assets.
In an interview with Rolling Stone magazine, she said: "God answered [my] prayer above and beyond, by, like, 100 times, until I was like, `Please, stop, God. I can`t see my feet anymore. Please stop!`
"I was a lot more rectangular then. I didn`t understand my body. So, what I did was, I started taping them down. How long did I tape them down for? Probably until I was about 19. And, no, I don`t have any psychological pain because of it."
Now she has made it in the music business, Katy has turned her attention to politics and is calling for "revolutionary change" in the US.
The 26-year-old pop star - who was born in Santa Barbara, California -added: "It just feels like the thing running our country (America) is a bank, money. I know it sounds like an intense viewpoint, but I`m only slowly but surely getting the wool taken off my eyes.
"I think we are largely in desperate need of revolutionary change in the way our mindset is. Our priority is fame, and people`s wellness is way low. I saw this knowing full well that I`m a part of the problem. I`m playing the game, though I am trying to reroute.
"Anyway, not to get all politically divulging and introspective, but the fact that America doesn`t have free health care drives me f***ing absolutely crazy, and is so wrong."