Tom Brady of the New England Patriots drinks on the sideline in the first half against the Denver Broncos in the AFC Championship game at Sports Authority Field at Mile High on Jan. 24, 2016 in Denver, Colorado. Christian Petersen/Getty Images

Few people are more careful about what they put in their bodies than New England Patriots quarterback Tom Brady — the man has never eaten a strawberry or taken a sip of coffee. But in a departure from his typical dietary caution, Brady revealed this week that when it comes to in-game hydration, he drinks a concoction with ingredients undisclosed to him.

The reason he imbibes the mystery drink, however, seemingly stems from his usual desire to ingest so-called clean foods. During an interview on WEEI's Kirk and Callahan Show, Brady said he eschews the typical choices of Gatorade or water, seemingly alluding at the sports drink's sugar levels.

"I have this lemon drink with a ton of electrolytes in it," Brady said. "It doesn't have any sugar. I just load it up on electrolytes and ... it just keeps me right where I need to be."

The four-time Super Bowl winner added that he wasn't even entirely sure of the drink's ingredient list. "I don't know how they make it. The training staff does it for me," Brady said. This, of course, could be the quarterback playing coy to keep the recipe for his "secret stuff" private.

Electrolytes are minerals in your body that you lose through sweat — such as salt or potassium — so it would make sense Brady would want to replenish with an electrolyte-laden drink. And it also makes sense he doesn't want to do so through sports drinks, considering they're products made by a soda industry the quarterback has railed against, once calling Coca-Cola "poison for kids."

"I think we’ve been lied to by a lot of food companies over the years, by a lot of beverage companies over the years. But we still do it. That’s just America, and that’s what we’ve been conditioned to,” Brady said in October 2015.

It's pretty widely known that sugary drinks are unhealthy, but Brady's incredibly strict diet goes way past cutting back on soda. Allen Campbell, personal chef to Brady and supermodel wife Gisele Bündchen, told the Boston Globe last year that the couples' diet is 80 percent vegetables with no sugar, white flour or MSG. And even when it comes to vegetables, Brady has a real problem with nightshades.

"[Tom] doesn’t eat nightshades, because they’re not anti-inflammatory. So no tomatoes, peppers, mushrooms, or eggplants," Campbell told the Globe. "Tomatoes trickle in every now and then, but just maybe once a month. I’m very cautious about tomatoes. They cause inflammation."

If you want to copy this peculiar diet — which some have tried with non-ideal results — you can buy Brady's "nutrition manual" for $200 on his website. Just don't expect a recipe for his secret stuff.