Katy Perry has quit drinking so she can be in top shape for her upcoming tour.

The Roar singer is preparing to kick off a huge world tour in May (14), covering countries including Britain, Australia and the U.S., and she has overhauled her lifestyle to make sure she is fit for the road.

Speaking on Australian Tv show Sunrise, Perry says, "I have to be very focused right now... I've cut out all alcohol and all fatty foods, a lot of dairies (sic), I go home and I'm gonna have mostly vegetarian with some protein on the side like some grilled chicken."

Perry, 29, adds of her decision to change her diet, "I'm almost 30 guys, my body does not snap back any more. I can't go around eating MCDonald's like I used to."