(CNN)Ask any parent about the influence of pop, rock and rap music on their teen's behavior, and you'll get an earful: Everything from what they wear, to how they style their hair, to what foods they eat can be influenced by that favorite artist.
It's the impact on the foods they eat that has many experts worried, as study after study points to the role of celebrity endorsements in our nation's epidemic of childhood obesity.
And it appears that many of our top music artists do a lot of unhealthy endorsements.
A study released Monday by NYU Langone Medical Center ranked a singer or group's popularity with teens and then looked at the type of foods and drinks they endorsed. Researchers say it's the first to apply a rigorous nutritional analysis to the review of dozens of advertisements by music stars over a 14-year period.
The study found that 79% of the promoted beverages were sugary drinks, and 80% of the foods were nutrient-poor. There were no endorsements for fruits, vegetables or whole grains, and only one food product with a healthy score: pistachios.
Who were the top celebrity endorsers?
Justin Timberlake recorded the "I'm Lovin' It" jingle for McDonald's and got a hit out of the deal. He's also endorsed Pepsi Regular.
Maroon 5, headed by singer Adam Levine, wrote a song for Coca-Cola and one for Snapple, which nutritionists say can be as sugar-laden as a soda.
Will.i.am had endorsements for Doritos, Coca-Cola, Dr Pepper and Pepsi.
And Baauer, best known for trap music like "Harlem Shake," led the pack with endorsements for Hot Pockets, Red Bull, Dr Pepper, A&W Restaurants and Pepsi.
According to the study, $2 billion a year is spent by food and drink companies on youth-targeted ads. It's estimated that children see 4,700 ads each year while teens view 5,900.
"These celebrity endorsement deals are often worth millions of dollars each, suggesting companies find them critical for promoting products," said lead study author Marie Bragg, a faculty member at the NYU College of Global Public Health. "Food advertising leads to overeating, and the food industry spends $1.8 billion per year marketing to youth alone."
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While many food and beverage companies have taken voluntary pledges not to target children under 12, Bragg said, teens are not included in that effort, but they should be, she said.
"The popularity of music celebrities among adolescents makes them uniquely poised to serve as positive role models," study co-author Alysa N. Miller added. "Celebrities should be aware that their endorsements could exacerbate society's struggle with obesity, and they should endorse healthy products instead."
Maroon 5 talk about going into a lab to create a new flavor for Snapple. The drink, 'Tea Will Be Loved,' is a blend of black tea, green tea, pomegranate, berries and citrus. The band, along with Snapple, also donated $250K to Feed America. (Sept. 2)