Jack Dorsey must have missed the “Everything in moderation” memo.

The Twitter and Square CEO recently opened up on Ben Greenfield’s “Fitness: Diet, Fat Loss and Performance” podcast about how he does it all, and revealed it comes down to his extremely limited diet. It’s so limited, in fact, that Dorsey barely consumes any food at all.

Dorsey, 42, explained that he eats just one meal every day at dinnertime between the hours of 6:30 p.m. and 9 p.m. Experts typically recommended three solid meals per day or six smaller meals throughout the day. Dorsey’s dishes usually consist of a protein (chicken, steak or fish) with vegetables (salad, spinach, asparagus or Brussels sprouts).

When the executive treats himself to dessert, it’s only mixed berries or dark chocolate. He’ll dabble with a glass of red wine, too.

“During the day, I feel so much more focused,” Dorsey shared. “You have this very focused point of mind in terms of this drive …”

Weekends, however, are a different story. Dorsey completely fasts from Friday evening to Sunday and only drinks water throughout these days.

“The first time I did it, like day three, I felt like I was hallucinating. It was a weird state to be in,” he recalled to Greenfield. “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.”

Dorsey’s extreme lifestyle doesn’t stop at food; he also uses a hydrotherapy routine that involves sitting in a sauna for 15 minutes at 220 degrees before jumping into a 37-degree ice bath for three minutes. He does this cycle three times in a row.

“Nothing has given me more mental confidence than being able to go straight from room temperature into the cold,” Dorsey said of his eye-opening routine. “Especially in the morning, going into an ice-cold tub from just being warm in bed is — it just unlocks this thing in my mind and I feel like if I can will myself to do that thing that seems so small but hurts so much, I can do nearly anything.”

If this doesn’t sound extreme enough, Dorsey also hinted that he might make even more drastic changes in order to “survive.”

“A lot of my routine today is all due to what felt like just had to be done in order to, not only survive but to make sure that I can continue to be performing and continue to be clear,” he continued. “Some practices have been impactful, some I’m not sure if they’ve been impactful just yet. … It only benefits me if I can raise the bar on myself.”