Is it humanly possible to eat 4,000 calories every day, like Mark Zuckerberg says?

Facebook magnate Mark Zuckerberg claims he trains Brazilian jiu-jitsu all day, so he needs to eat that much daily

Lead photo from Zuck/Instagram

I’m pretty sure you’ve heard the latest story to come out involving embattled X (formerly Twitter) owner Elon Musk. He was supposed to have a mixed martial arts fight against Facebook founder Mark Zuckerberg, who actively trains Brazilian jiu-jitsu.

Now, the fight is likely not pushing through after Musk constantly ducked and gave excuse after excuse. He’s not even in the same ballpark as Zuckerberg when it comes to shape and conditioning. However, the biggest story to catch my eye in this entire news cycle is Zuck’s casual declaration that due to his relentless routine fight training, he consumes 4,000 calories of food a day.

4,000 calories seems to be Mark Zuckerberg’s new maintenance calorie baseline because he also says he’s not looking to cut body fat or mass. That’s understandable, especially if one of his goals is to keep muscle mass and, in turn, strength while fighting

First, some context: 4,000 calories seems to be Zuckerberg’s new maintenance calorie baseline because he also says he’s not looking to cut body fat or mass. That’s understandable, especially if one of his goals is to keep muscle mass and, in turn, strength while fighting.

But that’s still a lot, and definitely a lot more than a normal human usually takes in in a day.

The insanity of 4,000 calories

However, all of this does beg the question: if you’re a serious athlete, how feasible is eating 4,000 calories a day, either financially or physically?

Let’s run a few estimations on Zuckerberg himself. According to the internet, Zuckerberg stands at 5’7 and 155 pounds. That’s pretty lean and going by some photos on social media, that’s mostly muscle. A quick trip to a basal metabolic rate (BMR) calculator shows that his estimated BMR is around 1,600 calories by default—and because he’s very active, the calculator estimates that the baseline is actually around 2,300 to 2,400 calories.

But how many hours of BJJ training does it take to have to eat 4,000 calories? The Fighter’s Guide says that even only a two-hour rolling session can burn up to 1,500 calories, especially when you keep at it that entire time. A reasonable estimate would be around two-and-a-half to three hours of rolling to burn 4,000 calories in one day.

That’s actually not a bad way to go about weight loss, and that’s pretty normal for most fighters and athletes. So if you want to start burning fat, now you know a good way to do it. Throw in your non-exercise active thermogenesis activity and you’ve got yourself a solid recipe to get leaner, if that is your goal.

The real insanity lies in how much food 4,000 calories actually is.

For reference, if you’re following a diet—either eating clean or restricting portions—you’re probably going to take in somewhere from 400 to 700 calories per meal. If you multiply that by three square meals a day, that’s usually just around 1,500 to 1,800 calories. Throw in some snacks and supplementation and you’ll likely hit 2,500 or go upwards and get close to 3,000.

Getting to 4,000 calories means you’ll have to stuff your face a lot. Either you’re eating a lot of junk for three or more meals a day or grabbing solid meals and snacks more times in a day than most ordinary people would like

Getting to 4,000 calories means you’ll have to stuff your face a lot. Either you’re eating a lot of junk for three or more meals a day or grabbing solid meals and snacks more times in a day than most ordinary people would like. Either way, you’ll be eating so much in frequency or in volume, I’m willing to bet good money that you’re going to get sick of it sooner than you think.

More importantly, anyone who’s come up with a diet plan and shopped for groceries for themselves knows that those costs will be exorbitant. That’s pennies for one of the richest people in the world, but if you’re not at least a professional athlete making millions to maintain a high-performing body, it will definitely be too much.

How does it affect your body?

It’s easy to assume that Zuckerberg gets to his 4,000 calories in a safe and clean way, considering he is training to fight. You can’t perform well on the mats if you’re eating junk (unless you’re genetically gifted like a few pro athletes).

If you’re highly active and need to get to 4,000 calories on most days, it’s best to not do it dirty (meaning, eating pretty much every high-calorie food you can get your hands on). The bad stuff may count towards your calorie quota and you may be exercising enough to offset it, but it can also have adverse effects on your body.

It’s easy to assume that Mark Zuckerberg gets to his 4,000 calories in a safe and clean way, considering he is training to fight. You can’t perform well on the mats if you’re eating junk (unless you’re genetically gifted like a few pro athletes)

There’s fat, heart disease, low energy, nutrient deficiencies, and more. You may also not get the macros (and micros) that you need, especially for recovery after long sessions in the gym, on the court, on the field, on the mats, in the ring, wherever you play.

So the TL;DR: If you’re doing 4,000 calories, if you have to do 4,000 calories—every day—there’s no choice but to do it right and clean. But also, it’s best to give yourself a double-check; maybe you don’t have to eat that much most of the time.