Is Intermittent Fasting Healthy for Work Culture?

Andrew Zaleski on 2020-02-05

Why therapists are worried that calorie restriction is now a productivity hack

Illustration: Nan Lee

In December, on the day after Christmas, an entire segment of Good Morning America was devoted to intermittent fasting.

Pioneers of human longevity science have long embraced the eating pattern, which they sometimes refer to as caloric restriction. Ingest less food, they say, and the body shuts down a crucial pathway for regulating cellular metabolism, putting cells into repair mode. The thinking is that humans age less quickly while cells are shoring up their defenses instead of growing and dividing.

Now a diet favored by people questing to live longer was getting airtime on a popular morning show. The message was clear. Intermittent fasting is no longer just the purview of folks like Jack Dorsey, the Twitter CEO who outlined his strict eating regimen during a podcast interview last year, revealing he doesn’t eat until 6:30 p.m. each day. The diet has broken into the mainstream. Last year, intermittent fasting was the most-searched diet on Google.

While some fasting diets are in the service of weight loss, the way intermittent fasting is often applied in the corners of Silicon Valley — where it seems to have cultivated an early following — falls under the rubric of mental clarity. Much like dunking butter in a cup of coffee or eliminating everything except animal protein on your dinner plate, fasting is another tool being used to boost brainpower throughout the day.

“[T]he first two weeks were really hard. … [A]fter I got over those first two weeks, during the day, I feel so much more focused,” said Dorsey last spring. “I think it’s just this very ancestral looking for where the food is. You have this very focused point of mind in terms of this drive.”

But there’s another side of this quest to optimize the self. What Dorsey characterizes as focus is what a nutritionist might call starvation, a darker psychology that concerns eating-disorder specialists and therapists alike. The eating pattern is backed by science, but it still raises concerns among some medical professionals.

“These fad diets have become another way to rationalize and legitimize disordered eating,” says Lauren Korshak, a therapist in San Francisco who works with people recovering from eating disorders. “These disordered patterns may turn into full-blown orthorexia or eating disorders.”

“We’ve worked so hard to get rid of the idea that restriction is good, and now CEOs are putting a value on it and saying this will make you be more productive. Bottom line is, you’re starving yourself.”

Elemental spoke with a half-dozen therapists and specialists in and around Silicon Valley about intermittent fasting. Many shared a skepticism about so-called optimization diets — and warned of their potential dangers. Some mentioned that several of their clients are either struggling with irregular eating patterns as a result of trying a fasting diet, or feel the pressure to try a fast or change how they eat because of how a fasting diet is characterized among co-workers: as a way to be more optimized.

“Diets resulting in eating disorders have been around for as long as diets have been around,” says Olga Rocklin, another therapist based in San Francisco. “Atkins, South Beach, the paleo, the keto, intermittent fasting — for some people, it’s fine. For a lot of people, it can kick up disordered eating.”

No two intermittent fasting diets are necessarily alike. Some people fast every other day; some eat regularly for five days straight and then fast the remaining two days. And then there’s “time-restricted feeding,” where any eating takes place during a narrow window and fasting occupies the remaining hours of the day.

Because fasting emphasizes the times when a person is or isn’t eating, as opposed to restricting certain foods outright, those on the diet usually characterize it as a way to reframe their thinking around conventional mealtimes. They might not even call it a diet. But no matter the framing, fasting for supposed cognitive or other gains that worries specialists like Rocklin.

“People are not looking at it as a problem because there’s this caveat that during the time you’re allowed to eat, you can eat whatever you want,” she says. “That can lead to disordered eating, and that can lead to eating disorders.”

The distinction is important, as eating disorders have their own diagnostic criteria developed by the American Psychiatric Association. The difference between disordered eating and an eating disorder amounts to the level of obsessive thinking about food coupled with a greater severity of coping mechanisms, and how that might affect the emotional state of a person on a daily basis. Though disordered eating usually carries symptoms that are similar to eating disorders — such as food restriction, for instance.

“The line where something moves from a diet that’s not pathological into the realm of a mental health problem is if it’s causing the person significant distress, they feel like their behavior is out of control, or if it’s starting to become impairing, like if they can’t socialize anymore,” says Tiffany Brown, a researcher at the Eating Disorders Center at the University of California, San Diego.

Shrein Bahrami, an eating disorder specialist based in San Francisco, says roughly half of her clients either work directly in the tech industry or are recruiters for tech companies; talk about various optimization diets often comes up. Many of the people she sees have been clients for some time — clients, she says, who have recovered from eating disorders. Now those same clients are having to navigate an industry where intermittent fasting as a technique can retrigger previous emotional distress.

“We’ve worked so hard to get rid of the idea that restriction is good, and now CEOs are putting a value on it and saying this will make you be more productive,” Bahrami says. “Bottom line is, you’re starving yourself.”

Advocates of intermittent fasting, while sensitive to the concerns around eating disorders, will note that doing a fast may help someone develop a more healthy overall relationship with food. “I understand the controversy,” says Geoffrey Woo, co-founder of San Francisco-based nootropics company HVMN. “But when I look at the normal corporate practices of happy hours every day after work, pizza, doughnuts, other food in the office, and people always snacking — that, to me, is more dangerous than a culture around fasting.”

At the offices of HVMN, where about three-quarters of employees do some sort of intermittent fasting or low-carbohydrate diet, blood fingersticks and glucose monitors abound. As Woo told Elemental last spring, it was only after he observed co-workers successfully take up a fasting regimen that he decided to try it as well.

“We don’t have a formalized policy around people for dietary protocols,” he says. “Given our company mission and culture, we attract people that are more open-minded or introspectively thoughtful around their dietary choices beyond what is pushed to them via traditional advertising.”

Woo jumped headfirst into fasting, embarking on an initial trial that lasted 60 hours. His early experiences were difficult. But once Woo pushed through his first two fasts, he began noticing a different set of effects: He was more focused throughout the day and less groggy. He says his blood sugar was no longer spiking and crashing as it might for someone who eats lunch.

Even people not immersed in an experimental office setting find fasting beneficial. There are a number of examples in and around Silicon Valley. Multiday fasting is how Phil Libin, the former CEO of Evernote, lost 80 pounds after learning he was pre-diabetic. Daniel Gross, a former partner at Y Combinator, fasts for the same reason guys like longevity enthusiast Bill Faloon fast: He thinks it will help him live longer.

An often-discussed example is Kevin Rose, co-founder of Digg, who became interested in intermittent fasting after learning it’s how Hugh Jackman got himself in shape to play Wolverine. In a post on Medium, Rose listed the benefits culled from “research published by scientists in peer-reviewed journals,” which showed him that intermittent fasting “improves sleep, has positive effects on markers of systemic inflammation, and regulates blood glucose levels and other aging biomarkers.” He also released an app, Zero, for people who would like to track their fasting.

“‘When I look at the normal corporate practices of happy hours every day after work, pizza, doughnuts…people always snacking — that, to me, is more dangerous than a culture around fasting.’”

For his own clients in Silicon Valley who have tried intermittent fasting, psychologist Cameron Sepah says it helps them meet nutrition goals by reducing impulsive eating, as well as relieving the pressure of deciding when they should eat.

“Clients often use it as one tool as part of a comprehensive weight-loss strategy,” says Sepah, who is also a professor of psychiatry at the school of medicine at the University of California, San Francisco. “They generally find it useful and are the ones that are coming in wanting to or are already doing it.”

It makes sense that such a diet takes hold in Silicon Valley — a place known, perhaps stereotypically, as “performance-oriented, which often leads to finding ways of optimizing health and productivity,” says Sepah, who is also known for promoting dopamine fasting. He adds that he hasn’t seen any sort of uptick in disordered eating at his own practice from clients trying out a fasting diet.

“Any behavior can be taken to an extreme,” he says. “But most intermittent fasting protocols are quite reasonable, and may approximate more traditional ways of eating.”

Specialists leery of diets carried out in the service of self-optimization are careful to note that intermittent fasting doesn’t directly cause an eating disorder. But the key element of intermittent fasting that makes Cox, Bahrami, Rocklin, and fellow colleagues unconvinced of its merits is the diet’s restrictive nature. Forgoing bodily cues of hunger is part of the fasting; it’s the very thing that leads someone to describe the feeling of a multiday fast as hallucinatory.

“The first time I did it, like day three, I felt like I was hallucinating,” Jack Dorsey said on the podcast last year. “The feeling of time slowed to a crawl where the day just went on and on and on, and I think it was because there was no meal to really, really separate the thirds of it.”

It’s very likely that what he was experiencing in that moment is something called cave-person brain, a term coined by Jennifer Gaudiani, an internist in Colorado and author of Sick Enough: A Guide to the Medical Complications of Eating Disorders. There is a type of initial superhuman feeling that people get when they restrict their eating for a prolonged period of time, which is a natural biological response: You’re being hypervigilant and more attentive because the cave person in you is searching out your next meal.

But it doesn’t mean that the feeling, despite how one perceives it in the moment, is validation of the fasting experience. There is some research that indicates that chronic restriction can alter the brain, shrinking it as gray and white matter are lost. “We call this a ‘starved brain,’” Gaudiani says. “[W]hen a person does not get adequate nutrition regularly, they’ll experience changes in their concentration, memory, fear response, and cognitive flexibility.”

If a fasting diet leads to obsessive thoughts about food or eating, the starved brain might only reinforce those compulsions, making them stronger over time. “The gateway drug to any eating disorder is dieting,” says Marcella Cox, an eating disorder specialist based near Redwood City, California.

While it’s just a subset of people attempting diets who develop eating disorders, some of the data compiled by the National Eating Disorders Association shows that even testing out a new diet can lead to complications. In a study conducted on college campuses, the Association found that roughly one-third of dieters become pathological, and that one-quarter of that group end up developing “full-syndrome” eating disorders.

When I posed these sorts of concerns to Woo, he mentioned that the first step for anyone interested in testing out a fasting diet should be to consult their doctor, especially if they’ve had issues with eating disorders or other health problems in the past. Asked about the potential dangers of intermittent fasting, Sepah had a counterintuitive take.

“Ironically, I think there’s much more danger in eating the way most Americans eat, which is eating all day, and constantly grazing or snacking all the time, which contributes to the obesity epidemic,” he says.

“There’s no one right way to eat. That’s my bottom line with clients,” Bahrami says. “But our stomach and gut is like our second brain, and we need to pay attention to that.”