NEW YORK-When Miami Heat star LeBron James isn't scoring baskets, he's busy-selling soda, sports drinks and fast food.
But James isn't alone. In a new study, many top U.S. athletes, from Peyton Manning to Serena Williams, were all over television promoting food and drinks, most of which aren't very healthy.
"We see these people-they've obviously (reached the top) of sports achievement, they're obviously living a healthy lifestyle-and they're endorsing these foods. And that kind of lends an aura of healthfulness to these foods and beverages that they don't deserve," said Emma Boyland, from the University of Liverpool in the UK.
"The message is really getting mixed up," added Boyland. She studies marketing and children's food choices but didn't work on the new research.
The new study was led by Marie Bragg from the Rudd Center for Food Policy and Obesity at Yale University in New Haven, Connecticut.
She and her team compiled a list of advertising deals for 100 top athletes. In 2010, those athletes endorsed a total of 512 brands. About a quarter were food and beverages.
The athletes endorsed 62 food products, including burgers, cookies and cereal. Forty-nine of the 62 were high in calories and low in nutritional value.
They also endorsed 46 sports drinks, sodas and other beverages. And in 43 of those, all the calories came from added sugar, the research team wrote Monday in Pediatrics.
"What stood out to us was the striking irony of the practice of having the world's most physically fit athletes endorsing these products," Bragg said.
Based on TV viewing data, Bragg's team found that teens saw more of the ads by athletes during the year than adults.
"We know that children and (teens) are really affected by this type of thing," Boyland told Reuters Health. "We know that influences the type of foods they choose and they eat."
It's also clear that such selling tactics work, researchers said. The proof, they say, is that companies will pay athletes millions to endorse a product.
Bragg said parents should be aware that many products being marketed to children may be of questionable nutritional quality.
"Just because they're athletes doesn't mean that what they're endorsing is healthy," she told Reuters Health.
She said putting limits on TV watching is one step parents can take to reduce the influence of marketing.
Kathleen Keller has studied food branding and eating habits at The Pennsylvania State University in University Park. She says parents should explain how advertising works to children.
That's because even if kids don't watch TV at home, they will still end up seeing ads all over the place, she told Reuters Health.
"Within your home you can really teach your kids from a young age about what the purpose of marketing is, what the purpose of advertising is," Keller said.