Tom Brady wasn’t built for football.

Stocky and a little slow at the 2000 scouting combine, the quarterback was picked up in the sixth round of the draft and promptly relegated to the Patriots bench.

Seventeen years later and about to play in his seventh Super Bowl on Sunday, 39-year-old Brady is looking at what could be one of the longest — and certainly most successful — careers in the NFL.

To hear Brady tell it, his longevity is largely thanks to his eccentric eating habits.

In late 2014, he explained his diet to Sports Illustrated as 80 percent alkaline and 20 percent acidic, which, he says, “maintain[s] balance and harmony through [his] metabolic system.”

Brady’s personal chef, Allen Campbell, broke it down further to Boston.com in January 2016: The quarterback eats 80 percent vegetables and whole grains, and 20 percent fish and lean meats, such as certain cuts of steak and duck. He doesn’t touch sugar, white flour or nightshade fruits and vegetables, which include tomatoes, peppers, eggplant, tomatillos, potatoes and certain berries. Fat comes from extra virgin olive oil on raw foods, and coconut oil on cooked foods.

Also on the list of banned ingredients: MSG, iodized salt, coffee, fungi and dairy. He only drinks alcohol occasionally.

And while his supermodel wife, Gisele Bündchen, follows the same diet — the couple’s two kids do a less strict version — they diverge on the subject of fruit. Though his family enjoys eating it, Brady limits himself to the occasional banana, blended in a smoothie. Unbelievably, he’s never eaten a strawberry, he told New York magazine in 2016. Rather, for a treat, he’ll have cacao avocado ice cream.

Everything that touches his table must also be organic. “If it’s not organic, I don’t use it,” Campbell told Boston.com.

Brady has to eat this way if he wants to keep playing, he told New York magazine in September: “I don’t believe you could be a 39-year-old quarterback in the NFL and eat cheeseburgers every day. I want to be able to do what I love to do for a long time.”

But is his alternative eating plan as healthy as he claims?

The most baffling tenet of Brady’s regimen is his adherence to an alkaline diet, based on science that New York-based registered dietitian Lauren Harris-Pincus calls “sketchy.” Followers believe that consuming so-called “acidic” foods, such as meat and dairy, will cause the blood to become acidic and promote disease growth.

‘I don’t believe you could be a 39-year-old quarterback in the NFL and eat cheeseburgers every day.’ - Tom Brady

Brady’s not the first celebrity to preach the diet, but experts say the eating plan lacks legitimacy. One of the diet’s loudest proponents, Robert O. Young, was convicted of two counts of practicing medicine without a license in California and faces up to three years and eight months in prison. (He’s due to be sentenced in May.) While Young has never worked with Brady, he praised the quarterback for following an alkaline diet in a 2016 blog post.

Still, Brady’s no stranger to questionable “experts” — his lifestyle guru and business partner, Alex Guerrero, was sued by the Federal Trade Commission for suggesting that a supplement he sold could cure cancer and other terminal diseases, and chastised for claiming to be a doctor (he has a master’s degree from a since-shuttered school of Eastern medicine).

In defense of Guerrero, who advises Brady on fitness and nutrition, Brady told Boston sports radio station WEEI in 2015, “When you say, ‘This sounds like quackery,’ well, there’s a lot of things I see on a daily basis in Western medicine that I think, ‘Wow, why would they ever do that? That’s crazy. It doesn’t work’ … I think a lot of things that are the norm, that are very systematic, don’t work.”

But experts say that the alkaline diet Brady subscribes to doesn’t work either: Eating foods with a high or low pH won’t change the pH of your blood in any significant way, Harris-Pincus explains.

“The bottom line is that our bodies have a very narrow window for pH, or we would die,” she says. Plus, “once everything hits your stomach, it’s all acid.”

And while Brady’s focus on eating vegetables and whole grains is laudable, his avoidance of nightshade vegetables appears misguided.

Brady avoids them out of fear that they can produce inflammation, which can cause joint and muscle pain and, down the line, diseases such as cancer. The problem is that science doesn’t exactly back up his concerns.

“There hasn’t been any real research that shows nightshades cause inflammation — even the Arthritis [Foundation] states that it’s a myth that nightshades are inflammatory,” says Harris-Pincus.

Plus, several of the items on his no-go list are incredibly healthy. “Tomatoes are high in lycopene, which prevents prostate cancer, so leading men away from eating tomatoes does them a disservice,” she says. Some studies have shown a link between tomatoes and a reduced prostate cancer risk.

Part of the issue with Brady’s diet, say experts, is its dismissal of major food groups such as fruit and dairy.

“The villainization of entire food groups is something we need to take off the table,” says sports nutritionist and Rumble boxing gym founding trainer Rob Sulaver, who notes yogurt can be a great source of both protein and gut-friendly probiotics.

And for a man who skips fruit, Brady still has no problem promoting Unreal Candy — a Boston brand that hawks additive-free, GMO-free takes on traditional sweets. In a video posted on his Facebook account last Halloween, Brady seductively bites into the company’s peanut butter cups.

Other elements of the superstar’s diet are based on half-truths, says Sulaver, such as his belief that heating extra virgin olive oil can produce toxins — a valid concern, but not at the temperatures at which one would cook most foods.

“[Olive oil] has a smoke point of around 400 degrees, so if you don’t burn it, it’s perfectly safe,” Sulaver says. “It’s a misunderstanding.”

As for his use of coconut oil in cooking, Harris-Pincus says she’s not convinced it’s healthy.

“I have no problem with a little bit of coconut oil, but I have a problem with people thinking it’s a health elixir [and using it excessively],” she says. “I don’t believe the science is there yet.”

Sulaver says that while he’s glad Brady talks about nutrition so openly, he’s concerned that the QB’s approach could mislead fans without a background in nutrition.

“I call it looking at science through a straw,” he says. “You’re looking at one aspect, but you’re missing the whole picture. It can be complicated, and the truth is in the details.”

Plus, Harris-Pincus points out, it’s easier to follow a diet like this when you don’t have to put in the time and effort.

“Let’s remember that he’s an elite athlete — he has money to hire a chef to cook fancy foods, and he probably has a very high food budget,” she says, noting that his organic-only ethos may turn off folks from eating conventional produce, which is still preferable to eating no fruits and veggies at all.

At the end of the day, she says, diets aren’t one-size-fits-all, and what clearly works for Brady won’t necessarily work for you.

So relax a little at your Super Bowl party this Sunday. Brady may turn up his nose at the fruit platter, but by all means, dig in.