Katy Perry Vogue Diet Revealed, Singer 'Glowing'

Katy Perry unveiled the secret behind her glamorous photo shoot for Vogue while speaking to Jay Leno recently.

The "Part of Me" singer graced the July cover of the respected fashion magazine for the first time, admitting that it was a lot of work on her behalf.

"I did a lot of my own prepping. I kind of went on a cleanse," said Perry while on "The Tonight Show" Friday.

The starlet is surely no stranger to the fruit and vegetable juice cleanses popular in Hollywood today, but noted other changes that made her "glow."

"I did a lot of stuff like vitamins and supplements, I changed my coffee to green tea, I didn't drink any alcohol for three months," said Perry speaking to Leno. "So I was really in the zone and just really wanted to be glowing for that cover."

Perry's appearance in the magazine included several whimsical photos of the singer posed in elaborate gowns. Renowned photographer Annie Leibovitz was behind the camera for the shoot.

The Vogue piece also featured an in-depth interview with Perry where she revealed that she was "still madly in love" with John Mayer.

"All I can say about that relationship is that he's got a beautiful mind," she said, according to the magazine. "Beautiful mind, tortured soul; I do have to figure out why I am attracted to these broken birds."

However, Perry and Mayer appear to have reconciled following the revealing interview, and Mayer even dedicated his song "A Face to Call Home" to her.

"She was so patient," Mayer told audience members at his concert in early July. "To continue to get to know me and love me."

Meanwhile, the 28-year-old singer is promoting her latest film "The Smurfs 2" (in which she provides the voice of Smurfette) and donned a royal blue dress on "Jay Leno."

Furthermore, Perry and her grandmother Ann Hudson attended the Los Angeles premiere of "Smurfs 2" on Sunday.

Britney Spears who collaborated with Perry on a song for the film also attended the premiere alongside sons Jayden James and Sean Preston.

"Smurfs 2" hits theaters on July 31, watch the trailer here.