Katy Perry, Pepsi Controversy: 'Roar' Singer Criticized for Promoting Unhealthy Lifestyle to Legions of KatyCats Following Unofficial Partnership

Katy Perry is in some sweet, sticky trouble. The "Roar" singer, who is celebrating the release of her third studio album Prism today (Oct. 22) is under fire from consumer advocacy groups for her partnerships with Pepsi. Groups such as the Center for Science in the Public Interest and Health Happens here accused Perry of promoting an unhealthy lifestyle to her legions of young, dedicated fans.

"One out of every three American children and teens is overweight or obese -- the science shows that drinking too much Pepsi, Coke, and other sugar drinks is a major cause of that," the open letter reads. "Each additional sugar drink consumed per day increases the likelihood of a child becoming obese by about 60 percent."

The letter also likened soft drinks to cigarettes and other tobacco products, sayig companies like Virginia Slims also "used glamorous celebrities and models to position smoking as hip, sexy, and rebellious." "'Drink Pepsi and you can be cool like Katy Perry' is the takeaway message for your young fans," states the letter, which letter begs Perry to "please stop."

Read the letter in full here.

Though Perry isn't an official Pepsi spokeswoman like fellow pop diva Beyoncé, she has teamed up with the soft drink company on several occasions. Most recently, she and Pepsi ran a social media contest leading up to the 2013 MTV Video Music Awards, where Katy Cats could vote on which new song, "Dark Horse" or "Walking on Air," would be released ahead of Prism.

Pepsi was also a sponsor for Perry's 2012 concert movie/documentary Katy Perry: Part of Me.