This week, two of the world’s richest tech moguls, Elon Musk and Mark Zuckerberg, appeared to agree to a cage fight. 

Musk tweeted on Wednesday night, bragging that he was ‘up for a cage match if he is.’ Meta boss Zuckerberg responded on Instagram: ‘Send me the location.’

Bookmakers already have Zuckerberg – who recently won a Brazilian Jiu-Jitsu competition and trains in mixed martial arts – as a clear favorite if the fight is to go ahead.

But how they fuel up before the fight could be crucial to determining who wins. 

Zuckerberg, 39, has been famously strict about his diet and exercise habits, only eating meat from animals he killed himself and competing in grueling workout challenges. 

Meanwhile, Musk, 51, has said that he dislikes working out and eats a donut every day, along with several cans of soda.  

In 2011, Zuckerberg decided to only eat meat if it was from an animal he killed. 

‘I think many people forget that a living being has to die for you to eat meat, so my goal revolves around not letting myself forget that and being thankful for what I have,’ Zuckerberg told Fortune at the time.

‘This year I’ve basically become a vegetarian since the only meat I’m eating is from animals I’ve killed myself. So far, this has been a good experience.

‘I’m eating a lot healthier foods and I’ve learned a lot about sustainable farming and raising of animals.’

Zuckerberg has owned several animals, including at least six goats. In 2021, he doubled the size of his Hawaii property with the aim to use it for farming.  

It is safe to assume Zuckerberg’s diet could be made up of organic chicken, fish, shellfish, beef, and even more exotic fare. 

In an interview with Rolling Stone, former Twitter CEO Jack Dorsey said that Zuckerberg invited him over for dinner one night and fed him cold meat from a goat that he had killed earlier. 

‘I guess he kills it. He kills it with a laser gun and then the knife. Then they send it to the butcher,’ Dorsey said. 

‘[Zuckerberg] had six goats at the time. I go, “we’re eating the goat you killed?” He said “Yeah,” I said, “Have you eaten goat before?” He’s like, “Yeah, I love it.”‘

It’s unclear if Zuckerberg still slaughters his own animals, but he has also admitted that he often forgets to eat. 

‘Do you ever get so excited about what you’re working on that you forget to eat meals?’ he wrote on Facebook. ‘Keeps happening. I think I’ve lost 10 pounds in the last months from this.’ 

Musk also has said he often prioritizes working over eating. ‘If there was a way that I could not eat so I could work more, I would not eat,’ Musk said in Ashlee Vance’s biography Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future. 

However, he’s less strict than Zuckerberg. In the past, he has said that he would either skip breakfast or eat something sweet, like a Mars bar or a donut. ‘I’m trying to cut down on sweet stuff, and I should have an omelet and coffee,’ he said, according to a 2017 article from Entrepreneur. 

A Mars bar contains 234 calories and 11.5 grams of fat. It also has 26 grams of sugar, nearly three quarters of the recommended daily sugar intake for men, which the American Heart Association says is 36 grams. 

He hasn’t seemed to make much progress in that respect. 

‘I eat a donut every morning. Still alive,’ he tweeted in March. 

The average plain glazed donut contains about 253 calories and 14 grams of fat. 

 It also has about 14 grams of sugar, or six and a half teaspoons. 

Last year, Musk tweeted a photo of his nightstand that showed four empty cans of caffeine-free Diet Coke. However, the drink has no calories or added sugar. 

He told Joe Rogan in 2020 episode of his podcast, ‘I’d rather eat tasty food and live a shorter life.’  

However, despite his relaxed diet, last year Musk admitted to taking weight-loss drug Wegovy, his secret to achieving a ‘fit, ripped, and healthy’ body, along with fasting. 

Wegovy is the sister medication to Ozempic, a brand name for the medication 
semaglutide. Wegovy and Ozempic work to suppress appetite and trigger weight loss. 

Already in 2023, doctors have doled out more than 832,700 prescriptions for Wegovy. 

Mr Musk has not said consistently whether the medication he took was branded Wegovy or Ozempic, but both medications can cause major weight loss and a reduction of body fat.

He said in October that he had lost nearly 30lbs with the medication’s help, in combination with fasting and ‘no tasty food’.

Coming in at 5′ 7″ (170 centimeters) and about 150 pounds (70 kilograms), Zuckerberg is the smaller and more nimble of the two businessmen. 

But in terms of fitness, Zuckerberg has been lauded for his intense workout regimens. 

Earlier this month, he completed the grueling ‘Murph Challenge’ workout, which involved completing 100 pull-ups, 200 push-ups, 300 squats, and a one-mile run. Not only did he finish, but he placed in the top 200 out of tens of thousands who have participated.

The challenge is named after Michael P Murphy, a US Navy SEAL who was killed on a tour of Afghanistan in 2005 and would regularly take on the brutal workout. 

Zuckerberg shared a photo of himself to Facebook wearing a camouflage weighted vest and another of his two daughters – August, 7, and Max, 5 – taking on a mini version of the challenge.

‘I try to do the Murph challenge with the girls every Memorial Day as a tradition to honor those who defended us,’ he wrote.

He also won both gold and silver medals in his first ever Brazilian jiu-jitsu tournament in May. 

Musk, however, has said that he has trained in Kyokushin karate, taekwondo, judo, and jiu-jitsu throughout his life. He also told CNBC that he spends a bit of time on the treadmill and lifting weights. 

However, he’s not a fan of exercise. ‘To be totally frank, I wouldn’t exercise at all if I could. I prefer not to exercise,’ he said on in an interview with Rogan. 

‘I have this great move that I call “The Walrus,” where I just lie on top of my opponent & do nothing,’ Musk tweeted on Wednesday.