When you hear someone eats just once a day, chances are your mind jumps straight to one conclusion: eating disorder. That’s certainly what happened when the internet heard Twitter CEO Jack Dorsey only picks a fork up once in a 24-hour window.
In an interview with CNBC, Dorsey revealed he eats just one meal a day between 6:30 and 9:30 p.m., which usually consists of “fish, chicken, or steak with a salad, spinach, asparagus or Brussels sprouts,” followed by some mixed berries or dark chocolate for dessert.
People are freaking out, but this isn’t actually that crazy, says Grant Tinsley, Ph.D., C.S.C.S., an intermittent fasting researcher and assistant professor of exercise physiology at Texas Tech University.
Dorsey’s approach falls under a form of intermittent fasting known as time-restricted feeding, which usually involves a feed window of four to eight hours, but technically encompasses any time someone is limiting their food intake to a particular window of time, Tinsley explains.
And it’s actually common enough to have an abbreviation: OMAD (that’s One Meal A Day).
But Is It Healthy?
To most Americans (and sane humans) subscribing to OMAD sounds like you’ll be underfed and bordering on an eating disorder.
It’s definitely possible to eat enough calories—or even too many—in a short, three-hour window, Tinsley says. Based on the meal plan Dorsey outlined, though, he may not be: Even if he’s being overindulgent on portion size, he’s probably only landing 500 to 800 calories a day, which may be less than he needs to maintain weight. But even though it’s not a meal plan that would be recommended for everyone, it’s possible, based on Dorsey’s own lifestyle, physiology, and workout regimen, that it’s enough for him, Tinsley adds.
The biggest point to consider, though, is how much his diet is interfering with his life and health, says Joann Hendelman, PH.d, R.N., clinical director of The Alliance for Eating Disorders Awareness. That’s the difference between disordered eating and an eating disorder: The latter is marked by an obsession with thoughts and behaviors around eating, especially one that starts to interfere with your emotions, social life, physical well-being, and mental well-being.
Dorsey’s diet, while super restrictive, doesn’t seem to restrict his life. He told CNBC that the first two weeks were hard but now he feels more focused, sleeps better, and relishes the time back most of us spend eating breakfast and lunch. Instead, his habits fall into the category of disordered eating—when you subscribe to a particular way of eating that doesn’t interfere with your daily life, lifestyle, or socializing.
In reality, we’ve all subscribed to disordered eating in one way or another for centuries, between historic famines or modern-day fad diets, Hendelman adds. But it certainly has its risks: Most restrictive ways of eating aren’t sustainable and diet crashes can wreak havoc on your body. Plus, after a while, the frustration of having to skip the pizza everyone around you is eating causes a lot of people to cut back on socializing, Hendelman points out. Mostly, outside of genetics, we don’t know what pushes people into an eating disorder, and altering the neurotransmitters in your gut via restriction could contribute, she adds.
On the other hand, Tinsley says, “Most healthy bodies can certainly tolerate a 20-ish hour fast each day if needed. There are points in human history where this was probably the norm.” And while OMAD definitely isn’t for everyone, he argues that it’s not inherently unhealthy and doesn’t lead to disordered eating.
Two studies—one in 2015 on alternate-day fasting and another published this year on time-restricted feeding—found IF had either no effect on eating disorder symptoms, like depression and binge eating, or actually helped reduce them.
“Someone who is performing IF should be aware of whether they may be susceptible to disordered eating, but the available evidence hasn’t shown that IF is problematic per se,” Tinsley adds.
And there’s a lot to be gained from regular fasts and restricting your feeding window: Research shows IF can help control cravings; improve body composition (and maintain the changes); potentially help control diabetes; reduce total cholesterol and triglycerides, thereby reducing cardiovascular risk; and enhance mitochondrial health, DNA repair, and stem cell-based regeneration. Dorsey swears OMAD helps him feel more focused—which Tinsley says may be part physiological but could also be the result of the mental bandwidth freed up by not dealing with food throughout the day.
Hendelman points out we don’t know the effects of following intermittent fasting long term and how it might interfere with your mental health and microbiome, and therefore the brain. But research shows pretty minimal risk to a healthy approach to fasting.
One point of concern: Dorsey told CNBC that he sometimes also does a weekend fast, going from Friday to Sunday with nothing but water. This is a little more concerning to Tinsley. “It’s still within the realm of something that could be safely completed by some people, but I would say this type of combined protocol is getting away from what may be feasible or recommended for most individuals performing IF.” It’s also worth noting, even during whole-day fasts, IF protocol calls for you to still eat 500 calories—the bare minimum your organs require to function and muscle requires to maintain.
Unless you’re genetically at risk for eating disorders or prone to obsessive thoughts, intermittent fasting can be a low-risk, high-reward way to heal your relationship with food, stop counting calories, and improve your health and body composition.
Don’t start with Dorsey’s program, though—plenty of people, including M.D.s, follow OMAD with no problems, and while we don’t know enough specifics to say whether Dorsey’s diet is actually healthy, Tinsley points out that it isn’t seeming to compromise his physical or mental health.
But for most people, a more feasible and sustainable IF program would be giving yourself 6 to 10 hours to eat within.