MrBeast's girlfriend showed him guzzling raw egg whites with chocolate syrup as part of his supposed productivity "grind"

• MrBeast's girlfriend, Thea Booysen, filmed him swigging egg whites and chocolate syrup.
• The YouTuber has been open about lifestyle habits he believes are required to be the most successful YouTuber in the world.
• He's also discussed living with Crohn's disease, which has necessitated a strict and repetitive diet.

Jimmy Donaldson, known to his legion of fans as MrBeast, has been open about the intense lifestyle choices he makes to become the most-subscribed YouTube star in the world. 

In a recent podcast interview, the YouTuber shared some thoughts on his "grind mode," saying he'll sometimes pull all-nighters or work for up to eight days straight before realizing he needs a moment to recharge, "and then go fucking binge a season of anime." 

"Normal people, they don't want that life," Donaldson told scientist Lex Fridman on his eponymous podcast. 

And on Wednesday, Donaldson's girlfriend – the Twitch streamer and author Thea Booysen – gave a rare, behind-the-scenes glimpse into what his unusual life can look like.

In a since-evaporated Instagram Story on Wednesday, Booysen filmed the YouTuber guzzling raw egg whites straight from the carton. In a subsequent story, Donaldson poured chocolate syrup into a cup filled with a yellowish-white liquid – presumably the egg whites, before swigging that down as well. "The grind is real," Booysen captioned the Story.

While it's unclear if it's a health or productivity hack, it's an undoubtedly curious concoction for the proprietor of several food brands. Donaldson is the owner of both the virtual food chain MrBeast Burger and the healthy snack brand Feastables.

Donaldson has also spoken openly about living with Crohn's disease, an inflammatory bowel disease that causes chronic swelling of tissues in the digestive tract. In a video posted seven years ago, Donaldson shared insight into how the diagnosis affects him and his limiting food options. "Whenever I eat certain foods, it agitates it," he said in the video. "And if it gets agitated, then I have enormous stomach pain that's really unbearable."

Accordingly, Donaldson must follow a strict and repetitive diet that "pretty much just sucks all the fun out of food," he said. He steers clear of fast food and cereal, for instance, and tends to favor chicken, rice, and sweet potatoes.

Insider has reached out to the YouTuber to learn more about his, erm, interesting concoction.