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OMAD—The Extreme Practice Of Eating One Meal A Day

by | Jun 21, 2020 | FASTING METHODS

The Big Idea behind OMAD. One Meal A Day

 Just. One. Meal. 

Before the recent explosion of interest in fasting, eating just once a day could have been considered an eating disorder. But things are a little different today, now that intermittent fasting is one of the most widely researched and practiced health interventions. The concept of eating six small meals per day to burn fat has been debunked. And eating less frequently – even just once – is looking saner by the day.

OMAD (short for ‘one meal a day’) is a simple and effective way to lose weight without the added stress of calorie counting. Studies have shown that this style of intermittent fasting helps shed unwanted fat withoutany calorie restriction, and it’s often used in conjunction with the keto diet to improve fat loss and satiety. 

Celebrities including Herschel Walker and General Stanley McChrystal have recently popularized OMAD as a long-term lifestyle.

When it comes to meal frequency and metabolic disease, fewer meals lead to lower levels of insulin, less fat storage and less inflammation in the body. Science has confirmed this in trials of time-restricted eating, proving that longer fasting windows produce more metabolic benefit. 

So if you can stomach a 20-hour fast each day, and you don’t have any medical conditions that would prevent you from longer fasting periods, OMAD may very well be the fasting method for you.

OMAD—The Extreme Practice Of Eating One Meal A Day

What it is 

With a name so definitive as ‘One Meal A Day’, you wouldn’t expect much confusion about what OMAD actually is. You eat only one meal, and poof – you’ve just done OMAD…right? 

But there actually is room for interpretation.

Some experts believe that OMAD is only truly OMAD when the daily meal is eaten in a 30 to 60-minute window. Others such as Gin Stephens say that an hour is unrealistic for shoveling in a whole day’s worth of food, and that eating all your calories within a 2 to 4-hour period is just as effective, and certainly worthy of the ‘OMAD’ title.

OMAD differs from the Warrior Diet in that it calls for a clean fast – you’re not allowed any snacks or calories before you get to your eating window.

Many OMAD practitioners break their fast with a snack or a small meal, finishing up their eating window with a large meal an hour or two later. (Athletes and individuals with high caloric requirements prefer this approach to OMAD.) Most of the scientific research on one-meal-a-day fasting has been conducted using a four-hour eating window, too. 

So generally speaking:

If you’re eating all your food with four hours, then you’re doing OMAD. (Just make sure you aren’t snacking on anything before your fasting window!) But if you want to be hardcore and cram all your victuals into an hourlong smorgasbord, that’s OMAD too. There just might not be any difference in doing so*.

*Editor’s note: As the science and strategies on fasting and time-restricted eating and health evolves, so will our reporting. We continue to update these pages with new research as available.


Fat Loss

In a 2007 study performed on 15 healthy adults over four months, eating one meal per day led to significant decreases in fat mass compared to the control group. Scientists hypothesized that the fat loss could have been due to metabolic changes that increased gluconeogenesis – the creation of glucose molecules from fat, – which happens after 4-6 hours of fasting.

Retained muscle

Referencing the above study on fat loss, researchers noted that OMAD did not lead to a decrease in fat-free mass compared to the control group. This means that only fat is being used for energy during an OMAD fasting window – not muscle.

Brain health

Short-term fasting has been shown to increase autophagy (cellular clean-up) in the neurons of mice. Since the accumulation of toxins and plaque in neural tissue are associated with a variety of neurodegenerative diseases, such as Alzheimer’s, fasting could delay those diseases and enhance brain health by cleaning up our wetware, so to speak.

There haven’t been any studies on 20-hour daily fasts and cognition, but improved memory and mental acuity are two common reasons that non-obese people stick with an OMAD regimen.


Jack Dorsey, CEO of Twitter, gave OMAD a celebrity boost when he said how much eating one meal a day enhanced his focus. In fact, intermittent fasting (including OMAD) is now commonly used for greater productivity and focus among executives and entrepreneurs the world over. This can be attributed to the obvious fact that less eating means less distraction, but also to the ketone bodies produced during a fast, which increase focus factors such as BDNF.


As with other forms of intermittent fasting, there aren’t any serious risks associated with OMAD such as refeeding syndrome. There simply isn’t enough fasting time to dramatically alter the body’s physiology in a negative way. That said, people with impaired liver or kidney function are always advised to check in with their doctors before trying an OMAD protocol, as these conditions would promote a higher risk for blood sugar and electrolyte imbalance.

Doctors recommend that people with a history of eating disorders (or who are prone to such disorders) pass on OMAD. 

Among the non-serious risks reported, hunger is the most common. Studies have even shown that hunger increases in OMAD participants compared to control groups over an eight week period. But other studies on time-restricted eating have shown that satiety actually improves with a reduction in meal frequency. Most people who practice OMAD find hunger either isn’t an issue or that it fades with time.

Headache, fatigue, and temporary diarrhea are also reported. But these symptoms can be reduced or eliminated by observing OMAD best practices.

How to Do it 

Putting OMAD into practice is simple, even if it may be more challenging than other intermittent fasting methods. All you have to do is decide whether you’ll eat in a 30-minute, 1-hour, or 4-hour eating window (most people choose to eat between 4:00pm and 8:00pm); eliminate snacks outside of your one meal; and then eat all of your calories for the day in your window. 

Here are some helpful tips that will make OMAD easier for you: 

  • Coffee and tea are 100% kosher any time throughout the day – and you can even sweeten with stevia or monk fruit powder. (Just don’t add sugar or cream.)
  • Hydrate with 10-20% more water than you normally do
  • Consider taking a full-spectrum electrolyte supplement, which will protect against heart palpitations and energy crashes
  • Work up to a full OMAD schedule by starting out with a week of 12-hour daily fasts, then a week of 16/8.
  • Add a tablespoon of apple cider vinegar to your water each morning to curb your appetite and promote fat burning.
  • Add half a teaspoon of sea salt to your water if you feel a headache coming on.
  • Take the weekends off and enjoy brunches and backyard barbecues

As with any other fasting method, make sure to consult your doctor before attempting OMAD or any other drastic change in your eating habits. 

fasting methods

Intermittent Fasting (IF)

Strategy that combines periods of eating with periods of fasting into a regular schedule.

Fasting With Water

The purposeful abstention of all food – solid or liquids – except for water. 

Dry Fasting

Dry Fasting

DF is the abstinence of food and water. Total. Abstinence. Dry!

Medical & Healing fasts

Medical & Healing Fast

Medical/therapeutic fasting is – eating nothing for medical advancements and natural healing.

Time Restricted Eating

The philosophy that aligns mealtimes with your natural circadian rhythm.

Fasting With Juice

Combine all your fruits & veggies into delicious juice for a select period of time.

Ketogenic Fasting

Ketogenic Fasting

Combines keto dieting principles with routine periods of fasting for enhanced fat loss. 

Fast for Religion

Spiritual & Religious

Spiritual and religious fasts have been part of almost every culture and religion throughout recorded history.

Prolonged Fasting

Fasting for 48 hours and over to
achieve health benefits and clarity.

Fasting With Food

Also known as Fasting Mimicking Diet (FMD), eating specific macronutrients to keep your body in a fasting state. 

Alternate Day Fasting

The idea behind ADF is simple – eat one day, don’t eat the next.

Detox Cleanses

Detox & Cleanse Programs

 Focus on improving liver health, the main detox organ, and nearly all of them enhance elimination and digestion.