29 November 2012, 11:03
The 'Part Of Me' star also admits she is struggling with her gruelling exercise regime.
Katy Perry has joked that she felt fat without wearing her "spanx" this week at the UNICEF Snowflake Ball in New York City.
The 'Teenage Dream' singer was pictured in a stunning navy blue down and matching cape for the high profile media event in the Big Apple, also attended by the likes of Selena Gomez and Una Thurman, but says she felt uncomfortable without wearing the popular body shaping undergarment.
"I feel like my [fat] is sticking out so bad right now," Katy joked to Us Magazine at the event. "I almost always wear [Spanx], but not tonight, and I feel it pushing out making me look fat!
"I like to say I run on the elliptical for 30 minutes watching CNN, but I don't do it often enough," Katy revealed, when asked about her exercise secrets. "So I'm just like, 'Oh I guess I'm not fitting into this Lanvin dress for these couple of months."
Check out a picture of Katy Perry attending the UNICEF Snowflake Ball 2012 this week below (Credit: Getty):
Last week Katy was pictured showing rumoured boyfriend John Mayer around her home city of Santa Barbara, California amid rumours the two are in the process of searching for a house to share in Los Angeles.
Katy Perry is also working on her third studio album at present after reuniting with regular collaborators Greg Wells and Bonnie McKee, who both contributed to her successful 2010 album 'Teenage Dream'.