Earlier this week, Twitter and Square CEO Jack Dorsey shared some of his "wellness" habits to CNBC. Some of his recommendations are actionable and achievable for most people, like taking time to meditate or journaling to keep track of important events that happen each day. Some of Dorsey's routine would be great for most people, but not particularly practical, like working at a standing desk or sitting in a sauna every day. And then there are his dietary habits.
Dorsey revealed in the interview that he limits himself to one meal per weekday—typically a pretty light offering that consists of "fish, chicken, or steak with a salad, spinach, asparagus or Brussels sprouts" with a dessert of "mixed berries or some dark chocolate" paired with a glass of red wine. During the weekend, Dorsey forgoes food altogether. After dinner Thursday, he skips meals on Friday, Saturday and most of Sunday before opting to eat dinner again Sunday evening.
What Dorsey is taking part in are forms of fasting. He's doing intermittent fasting during the week and periodic fasts during the weekend. However, given his caloric intake when he does eat—the Washington Post theorized its as little as 1,000 calories per meal—it's safe to say his practices are all on the extreme side. It's possible that Dorsey's routines may well work for him and could be monitored and guided by a medical professional. But these eating habits are not a viable option for most people and definitely aren't the "biohacks" they were presented as.
There is some evidence to suggest there are health benefits associated with intermittent fasting, including boosting energy and losing weight. Mark Mattson, a professor of neuroscience at Johns Hopkins School of Medicine, has suggested the practice can also help stave off neurodegenerative diseases like Alzheimer’s and Parkinson’s.
However, it's hard to say just how beneficial fasting is. The science is still out on how it affects people, and many of the positive associations with the practice come from studies performed on animals, according to Patricia Bannan, MS, RDN, a professional nutritionist and healthy cooking expert. "While there are some studies on intermittent fasting in humans that have shown beneficial results, more studies need to be conducted in humans, which can be complicated to perform," she said.
When intermittent fasting does work, it's typically done in a much more limited fashion than what Dorsey practices. One popular method is called the "5:2 diet," which encourages people to spend five days eating a normal, healthy diet while limiting intake to under 500 calories for two, non-consecutive days during the week. Even these types of fasting diets can prove unsustainable for many people. A 2017 study comparing fasting to a more standard form of dieting. It found 25 percent of people in the fasting group dropped out compared to just 10 percent in the regular diet group.
There is even less evidence to suggest fasting in a manner like Dorsey does will produce healthy outcomes, and one would be hard pressed to find a nutritionist or dietitian who would recommend it. Alissa Rumsey, MS, RD, owner of Alissa Rumsey Nutrition and Wellness, said that she wouldn't advise people try to replicate Dorsey's extreme form of fasting.
"Food provides energy, something that we need throughout the course of a day - so eating just once per day, and fasting for several days in a row, is not something I recommend," she said. Rumsey noted that research on intermittent fasting is mixed and it's best for people to find a diet that they can stick to. "Diets like this are based upon external factors, rather than listening to your own internal body cues."
While Dorsey claims some positive outcomes from his fasts including improved focus and better sleep, his description of his experiences while fasting are troubling. He said the first time he went without food for three days, he felt like he was hallucinating. "Hallucinating after not eating is not a good thing, Rumsey said. "It's a sign that your body needs energy and nutrients."
As for some of the claimed health benefits, experts have their doubts about that, too. "Research actually shows the opposite [regarding the ability to focus]—that eating balanced meals throughout the day is what helps to boost concentration, focus and work performance," Rumsey said. There is also evidence to suggest that fasting can cause disruptions to the sleep cycle, which can cause other negative health outcomes.
There's nothing wrong with trying to find a dietary option that works for you, especially if you are guided by an expert. Sustainability and overall health are key. If you're hoping to find success by copying the dubious and even troubling practices of a multi-millionaire and his "biohacks," you may want to reconsider that plan. "Extreme fasting like this carries a lot of risks and is not something I recommend," Rumsey said.
