You’ve probably already heard about this shocking new study in the scientific journal Pediatrics, the one that revealed that a lot of famous athletes shill for junk-food manufacturers.

Here’s how it worked: Researchers for the Rudd Center for Food Policy and Obesity at Yale University examined the endorsements of America’s 100 most prominent athletes, assigning each one an “Athlete Endorsement Index.” The lower the athlete’s score, the more negative his or her impact on America’s collective health.

Topping -- or, rather, bottoming out -- the chart was Denver Broncos quarterback Peyton Manning, whose tireless marketing efforts on behalf of Papa John’s pizza, Gatorade, Wheaties Fuel (“Winning takes intense preparation. It starts with Wheaties Fuel,” says Manning of the cereal with more sugar per serving than Cinnamon Toast Crunch), Pepsi and other goo earned him a lowly 28.9. Did I forget to mention Manning's labors on behalf of Double Stuf Oreos?

Even LeBron James, who hawks Big Macs and has his own flavor of Bubblicious bubble gum, looks like Michael Pollan next to Manning. (James came in at 42.8.)

Before we go further, it’s worth noting that Manning’s TV commercials may not be advancing the dietary interests of our nation, but judged on their artistic merits, they’re actually kind of funny. In addition to being a pretty decent quarterback, Manning is a very good actor, especially for an athlete. He also has a sense of humor about his own shamelessness. In 2007, he guest-starred on Saturday Night Live and joked about the fact that he had just accomplished two of his life-long goals: winning a Super Bowl ring and appearing in more than half of America’s TV commercials. (The episode also included this priceless skit.) There’s even a little irony in some of his commercials, most notably the Manning brothers’ mid-field Double Stuf lick-off.

The Rudd study was obviously meant to shame Manning and his fellow multi-million-dollar junk-food endorsers into reconsidering this particular revenue stream -- and to encourage them to use their power for good, not evil. As the article in Pediatrics stated: “Professional athletes are in a unique position to use their highly visible status to promote healthy messages to youth, and their role as athletes may lead the public to perceive them as credible sources of knowledge of a healthy lifestyle.”

This all seems pretty silly. To begin with, anyone who watches television doesn’t exactly need a scientific study to inform them that plenty of athletes front food and beverages that are “nutrient-poor.” Also, is crappy pizza really any worse for America than, say, high-interest credit cards? (Come to think of it, Peyton also promotes those!)

I'm all for raising awareness about healthy eating, but I fail to see why that’s the responsibility of professional athletes. We are long past the point of debating whether athletes are role models. (See: Tiger Woods, Aaron Hernandez and far too many others to count.) They are just athletes, trying to maximize earning potential before they become ex-athletes, sitting in front of their TVs scarfing down Cheetos.

(Jonathan Mahler is a Bloomberg View columnist. Follow him on Twitter.)