Grassland Beef - U.S. Wellness Meats
  1. Discover Blog
  2. /
  3. Diet
  4. /
  5. Paleo
  6. /
  7. Is One Meal a Day (OMAD)...

Is One Meal a Day (OMAD) Right for You?

hiker enjoying view on mountain top, feast fast, ancestral, omad

By Kelley Herring

For decades, we’ve been told to “eat three square meals” a day. We’ve been reminded to snack between meals to “keep energy levels up” … and to never skip breakfast, which has long been called “the most important meal of the day”.

But what if everything we’ve been told about when to eat is woefully wrong?

In today’s article, you’ll learn how eating breakfast could actually be harmful to your health… an ancestral way of timing your meals to boost brain health, fight chronic disease and improve body composition … plus the benefits and risks, and how you can get started.

Is Breakfast Really the Most Important Meal of the Day?

Of course, you’ve heard the adage that, “Breakfast is the most important meal of the day.”

But you’ve probably not heard where this conventional wisdom originated…

It certainly didn’t come from the results of a clinical study. Instead, it was from a 1944 marketing campaign, launched by General Foods. And the goal was not to improve our national health… it was to sell cereal!

In fact, what the studies do say is that this well-known adage is unfounded. A review of studies, published in the journal Frontiers in Health and titled Breakfast: To Skip or Not to Skipi concludes that:

Recommendations regarding breakfast eating are perhaps the most scientifically (especially metabolically) groundless health guidelines.”

Other studies suggest that eating breakfast – and certainly the breakfasts most people consume – is potentially as harmful as eating late at night. It’s well known that “late eaters” are more likely to gain weight. Studies also show they experience a greater number of health problems, compared to those who put down the fork and do not open the refrigerator after 8 pm.ii

But did you know the same thing is true for habitual breakfast eaters? Like late eaters, they also have higher incidence of medical claims than breakfast skippers and those who stop eating before dark.iii

Eating this way puts your metabolism into a natural state of…

OMAD, one meal, feast and fast

Feast & Fast: Striking the Perfect Ancestral Balance

Just like the flawed conventional wisdom about breakfast, you’ve probably also heard that the way to “keep your metabolism up” is to eat three square meals – plus several snacks – throughout the day. This advice is not grounded in science. And it does not fit within our evolutionary history.

In a study, titled Meal Frequency and Timing in Health and Disease, published by the National Academy of Sciences, iv the researchers state:

The most common eating pattern in modern societies – three meals plus snacks every day – is abnormal from an evolutionary perspective.”

This should go without saying: Humans were never meant to eat three scheduled meals and snacks in between. Our ancestors ate when food was available.

These regular cycles of “feast” and “fast” allow for cellular growth while eating… and cellular cleansing during the fast.

In my previous articles, you learned about the many health benefits of intermittent fasting (IF) – the simple practice of eating in a compressed time window. Now let’s learn about how you can take IF to the next level…

What is OMAD?

OMAD stands for One Meal a Day.

And in the nutrition world, it is considered the apex of time-restricted eating.

Unlike most ways of eating, OMAD doesn’t specify when or what to eat. The goal is simply to condense all of your eating into a one-hour window, with the other 23 hours in the day being food-free.

Building on the concept of intermittent fasting – which typically involves skipping breakfast and compressing your eating window into eight out of the 24 hours in a day – OMAD takes this concept a step further.

Health Benefits of OMAD

Most of the research currently published focuses on “time-restricted eating”, which can include:

  • Intermittent Fasting (IF) – with different options for when to eat (early vs. late)

  • Intermittent Energy Restriction (IER) – a method of fasting or reducing daily intake intermittently (for example, every other day)

  • One Meal a Day (OMAD)

Let’s take a look at the many ways that eating in a compressed time window can improve your health.

A 2019 study, published in the journal Nutrients, evaluated the effects of time-restricted eating on blood sugar, circadian rhythm and aging.

In the study, the early time-restricted eating (eTRF) participants ate between 8 am and 2 pm each day. The control group ate from 8 am to 8 pm. Both groups ate the same three meals, with a macronutrient ratio of 50% carbs, 35% fat, 15% protein. Participants in both groups wore continuous blood glucose monitors.

Researchers found the eTRF group, which stopped eating at 2 pm, had:

  • Lower 24-hour glucose levels

  • Lower mean glucose levels when asleep

  • Significantly lower insulin levels

What’s more, eTRF tended to increase morning cortisol levels and decrease them at night (an ideal pattern for optimal health). This would suggest an improvement in circadian rhythm. In fact, the researchers found “wide-sweeping changes in circadian clock gene expression”. Six out of eight circadian genes they tested were positively affected by the change in the eating window.v

Of course, because the participants all ate the exact same meals – the only variable that produced these health-promoting changes was meal timing!

Another study, published in the International Journal of Obesity looked at how intermittent energy restriction (IER) affected health and disease risk.

When human subjects switched from eating three full meals per day to an IER diet – such as one moderately-sized meal every other day or a very low-calorie diet (500–600 calories) two days per week – they exhibited robust changes in energy metabolism, including:

  • Increased insulin sensitivity

  • Reduced levels of insulin and leptin

  • Mobilization of fatty acids

  • Elevation of ketone levels viviiviiiix

What’s more, IER has been found to increase production of trophic factors that promote the survival and regeneration of neurons and the formation and strengthening of synapses in the brain.x

These studies clearly indicate that when you eat may be as important as what you eat!

comfort food, junk food, sugar free, healthy snacks

How to Safely Embark on OMAD

Instead of jumping from a standard three-meals-a-day eating pattern right into OMAD, it is important to ramp slowly to this level to help your body acclimate to the metabolic change.

A good way to do this is to begin with simple 16:8 intermittent fasting, where you finish eating dinner at 8:00 pm and then skip breakfast the next day – enjoying your first meal at lunchtime (12:00 pm).

Once you feel comfortable at two meals a day, alternate between two meals per day and OMAD. For example, Monday eat two meals with 16:8 time-restricted eating. Tuesday, eat one meal a day (OMAD). Wednesday eat two meals with 16:8 time-restricted eating.

It is very important to stay well-hydrated with any form of time-restricted eating. And tailor your time-restricted eating schedule to your needs. Most people find that the ideal eating window for OMAD is between 4 pm and 7 pm. This allows you to enjoy dinner with your friends and family and to fully digest your food before going to bed.

Risks of OMAD

Now that you’ve learned about the many benefits of OMAD, it’s important to note that this restricted way of eating is not appropriate for everyone.

Those with eating disorders, who are underweight, or who are pregnant or nursing should not try an OMAD pattern. Similarly, OMAD may not be appropriate for athletes or those on certain prescription medications.

In addition, OMAD can pose challenges for meeting protein requirements. Because protein is satiating, it can be difficult to get your entire protein requirement in a single sitting.

Carbohydrate loading can be another concern for those who are insulin resistant. When you condense your eating into a one-hour window, you also condense your carb intake during that period. If you are eating a carb-rich meal, this can lead to glucose and insulin spikes. It is important to keep this in mind if you are diabetic or pre-diabetic.

Another potential downside of OMAD is digestive upset. This may occur initially. The new cycle of feasting and fasting can cause changes to the microbiome, which may cause temporary abdominal discomfort.

If you feel dizzy, nauseated or very fatigued on OMAD, this way of eating may not be right for you. Always listen to your body. And consider talking to your healthcare provider about what eating pattern and style is right for YOU.

Nutrient-Dense Sample OMAD Menu

Now that you’ve learned about how OMAD works, as well as the risks and benefits, you might be wondering what you should eat. This is an important consideration, because you only have one eating opportunity to meet your nutritional needs.

While some people do OMAD irresponsibly, eating high-calorie, low-nutrient processed foods like an entire large pizza, the right way to do OMAD is in alignment with our ancestral blueprint.

Here’s a delicious and highly nutrient-dense sample OMAD “multivitamin meal”:

  • Balsamic-Berry Chicken Liver Salad: 3 oz. chicken livers sautéed in 2 Tbsp. grass-fed butter, over 2 cups of organic arugula with ½ cup organic raspberries and organic balsamic dressing

  • Grass-Fed Ribeye: 6-8 oz. grass-fed beef ribeye, grilled or pan-sautéed

  • Superfat Mashers: Cauliflower mash with grass-fed butter and organic heavy cream (or coconut cream)

  • Dark Chocolate: 2 oz. dark chocolate (either 70% cocoa or higher; or stevia sweetened)

Have you tried OMAD? If so, what was your experience with this way of time-restricted eating?

Read more of Kelley Herring’s health & wellness articles on our Discover Blog.

kelley herring


Kelley Herring is the author of the brand new book Keto Breads – which includes more information you need to know about why it is so important to avoid wheat and grains in your diet, plus how to use healthy replacements for these foods to create all the breads you love… without the gluten, carbs and health-harming effects. Click here to learn more about Keto Breads

Sources & References

i Cleator J, Abbott J, Judd P, Sutton C, Wilding JPH. Night eating syndrome: implications for severe obesity. Nutr Diabetes (2012) 2(9):e44.10.1038/nutd.2012.16

ii Baron KG, Reid KJ, Van Horn L, Zee PC. Contribution of evening macronutrient intake to total caloric intake and body mass index. Appetite (2012) 60(1):246–5110.1016/j.appet.2012.09.026

iii Okamoto E, Hiratsuka Y, Otsubo K, Kumakawa T. Evaluation of the health check up and guidance program through linkage with health insurance claims. J Natl Inst Public Health (2013) 62(1):13–30

iv Mattson MP, Allison DB, Fontana L, et al. Meal frequency and timing in health and disease. Proc Natl Acad Sci U S A. 2014;111(47):16647–16653. doi:10.1073/pnas.1413965111

v Humaira Jamshed,Robbie A. Beyl,Deborah L. Della Manna,et al. Early Time-Restricted Feeding Improves 24-Hour Glucose Levels and Affects Markers of the Circadian Clock, Aging, and Autophagy in Humans. Nutrients 2019, 11(6), 1234;

vi Johnson JB, Summer W, Cutler RG, et al. Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma [published correction appears in Free Radic Biol Med. 2007 Nov 1;43(9):1348. Tellejohan, Richard [corrected to Telljohann, Richard]]. Free Radic Biol Med. 2007;42(5):665‐674. doi:10.1016/j.freeradbiomed.2006.12.005

vii Harvie MN, Pegington M, Mattson MP, et al. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. Int J Obes (Lond). 2011;35(5):714‐727. doi:10.1038/ijo.2010.171

viii Klempel MC1, Kroeger CM, Varady KA.Alternate day fasting (ADF) with a high-fat diet produces similar weight loss and cardio-protection as ADF with a low-fat diet.Metabolism. 2013 Jan;62(1):137-43. doi: 10.1016/j.metabol.2012.07.002. Epub 2012 Aug 11.

ix Varady KA, Bhutani S, Klempel MC, et al. Alternate day fasting for weight loss in normal weight and overweight subjects: a randomized controlled trial. Nutr J. 2013;12(1):146. Published 2013 Nov 12. doi:10.1186/1475-2891-12-146

x Marosi K, Mattson MP. BDNF mediates adaptive brain and body responses to energetic challenges. Trends Endocrinol Metab. 2014;25(2):89‐98. doi:10.1016/j.tem.2013.10.006