Twitter CEO Jack Dorsey has been very open about his unusual eating habits. In the past, Dorsey has experimented with everything from the more mainstream vegan and Paleo fads to a more rigid routine of intermittent fasting.
Now, Dorsey’s unusual eating habits have again garnered a lot of attention, and criticism, after he discussed them on a recent podcast episode.
He told host Ben Greenfield — a fitness influencer who tweeted “anti-vaxx” comments last month — that he eats only one meal a day during the workweek, then fasts for the whole weekend.
“The first time I did it, like day three, I felt like I was hallucinating,” Dorsey said. “It was a weird state to be in. But as I did it the next two times, it just became so apparent to me how much of our days are centered around meals and how — the experience I had was when I was fasting for much longer, how time really slowed down.”
People on the internet took notice of Dorsey’s diet, and many remarked how much his routine sounds like an eating disorder.
Dorsey is far from the only tech billionaire to play around with unique eating habits and controversial diet fads.
Steve Jobs was known to go weeks eating only one or two foods at a time — once, it was strictly carrots and apples. Mark Zuckerberg made it his “personal challenge” in 2011 to eat only meat from animals he’d killed himself.
The Silicon Valley elite have long been enamored of “biohacking,” following certain routines and foods that may (or may not) get people to live longer and better lives.
The founder of Bulletproof Coffee, Dave Asprey, has biohacked his life with the goal of living until he’s 180 years old.
There’s a whole movement of techies who have taken on intermittent fasting, like Dorsey, as a way to biohack their lives.
There’s some science behind the fad that shows intermittent fasting can be just as helpful for weight loss as traditional diets. While the diet’s benefits have been apparent in the short term, studies have also shown it’s hard to stick with and could lead to dehydration if not done correctly.
Many are pulled to the diet because when you can eat — in the defined window of the day — you don’t have to count calories or ban carbs. Dorsey said his one meal a day includes fish, chicken, or steak with a side of vegetables.
This post originally appeared on Business Insider.