When Twitter and Square CEO and co-founder Jack Dorsey shared his rigorous "wellness" routine on a podcast in March, his habit of eating one meal a day, and sometimes going all weekend without eating, raised eyebrows.
At the time, he told podcast host Ben Greenfield that so-called intermittent fasting helps him focus and "has been a new dimension."
On Tuesday, there was an update to his controversial fasting habits.
These days, Dorsey eats "seven meals every week, just dinner," he told Wired in an interview posted on YouTube, which likely means Dorsey is no longer skipping food on weekends.
According to his previous comments, dinner for Dorsey is "a really big meal" that consists of protein like fish, chicken or steak, and "a lot of greens," including arugula or spinach salad, asparagus or Brussels sprouts. "And then, I have mixed berries as a dessert, maybe some dark chocolate," he said in March. (A moderately active man in their early 40s requires an estimated 2,600 calories a day, according to the Dietary Guidelines for Americans.)
Though intermittent fasting — in which you eat for a set window of six to eight hours and fast for the remainder — has become trendy in Silicon valley and among celebrities like Terry Crews and Jennifer Aniston, there hasn't been enough research on humans to determine whether it's sustainable or healthy long term. And experts agree that fasts lasting longer than 12 hours can be dangerous, especially for individuals who have specific health conditions or take certain medications, according to the National Institutes of Health.
Dorsey also told Wired he tries to meditate for two hours every single day.
Dorsey practices an ancient form of meditation called "vipassana," which is "extremely painful and demanding physical and mental work," he said in 2018.
Vipassana requires that people sit cross-legged for 30 to 45 minutes without moving. "[I]nstead of unconsciously reacting to feelings of pain or pleasure, consciously observe that all pain and pleasure aren't permanent, and will ultimately pass and dissolve away," Dorsey previously tweeted.
In the past, Dorsey has also talked about alternating 15-minute saunas and three-minute ice baths for an hour, telling Greenfield that the habit "has had probably the largest impact just in terms of how I feel but also mental clarity." (Some studies suggest that using a sauna regularly may improve your mood. But more research needs to be done on the effects of switching between extreme cold and heat.)
However Dorsey clarified to Wired: "I definitely do not do a sauna and ice bath every day."
Dorsey isn't the only tech billionaire to have eccentric eating habits. Apple co-founder Steve Jobs used to fast for periods of time, and would only eat fruit, nuts, seeds and grains, according to Walter Isaacson's biography, "Steve Jobs." And Microsoft co-founder Bill Gates would eat powdered Tang packets in the early days of the company, because he didn't want to take time away from working to eat.
Like this story? Subscribe to CNBC Make It on YouTube!