Tom Brady is doing a lot of things that he shouldn't be doing these days. He has helped take the New England Patriots to an undefeated 4-0 start, succeeding in overturning a four-game ban by the NFL for cheating allegations stemming from underinflated footballs. He's also playing some of the best football of his storied career, leading the league with a quarterback rating of 121.5 and completing nearly 73% of his passes. You don't see that very often in a 38-year-old pigskin hurler. 

However, Brady is also taking shots at Coca-Cola (NYSE:KO) and Kellogg (NYSE:K) this week, blasting both companies for their sugar products. 

Brady was defending his personal trainer on a Boston radio station WEEI-FM on Monday, and he decided the best strategy would be to point the finger back at the critics. He said that they were hypocrites for calling out his trainer when they were putting junk into their bodies. 

"I think that's quackery," he said, describing the large sums of money spent by Coca-Cola to promote its namesake beverage. "And the fact that they can sell that to kids? I mean, that's poison for kids."

He also took a bite out of Tony the Tiger, saying Kellogg's sugarcoated Frosted Flakes is part of the reason why this country has a childhood obesity problem. 

Both companies naturally fired back, trying to take the high road in order to not be dragged into a war of words that would hurt more than help their brands. Coca-Cola responded that it offers more than 200 low-calorie beverage options in North America. It also offers non-diet sodas in small cans as a serving option to reduce caloric intake. 

Kellogg countered by referring to studies showing that cereal breakfasts are tied to lower body mass index readings in both children and adults. Kellogg points out that a bowl of Frosted Flakes with skim milk packs just 150 calories with plenty of desirable nutrients. 

Did Brady just make himself that much less marketable? Is he the NFL's version of Food Babe? Can the Patriots continue winning?

It's ultimately Coca-Cola and Kellogg that have more to worry about than Brady here. Coca-Cola knows that folks aren't drinking sugary soft drinks the way that they used to. The U.S. carbonated soft-drink market has declined for 10 straight years. Why do you think Coca-Cola has spent the last few years diversifying into new beverage lines? 

Kellogg isn't necessarily in a better boat. Cereal consumption peaked in the 1990s. The industry isn't battling health concerns as much as it's dealing with drive-thru breakfasts, exotic yogurts, and other grab-and-go options for morning fuel. 

It's not cool to get called out by Brady, but both of these brands were meandering long before the controversial yet ultimately successful NFL star took them to task for pumping sugary products out there.