One Meal a Day: What Benefits Does It Bring?

Written and Medically Reviewed by Dr Babar Shahzad, BSc and MBBS on January 16, 2020.

One meal a day, or simply OMAD, is yet another form of intermittent fasting. The idea behind is simple: you only eat once a day and fast for the rest of it. Now if you are familiar with other forms of IF, you have already heard of 16:8 or 20:4 (ratio of fasting hours to eating hours) eating schemes. The OMAD aims at 23:1, boasting the highest fasting to eating ratio. This makes it in a way the most extreme form of IF; yet not necessarily the most challenging one.

In what follows we will explore the OMAD’s landscape: what is it; what are its key benefits and risks; how to get the most of it; and how to stay on track once you decide to go for it.

START QUIZ

OMAD: Intermittent Fasting on Steroids

If you are a more advanced user or work with a professional dietitian on creating your personal fasting schedule, you know that there are two main variables to consider: the duration of the fast and the length of eating window. Normally, IF regimes focus on the former: lighter versions make fasting windows shorter, and the most extreme versions have them as long as 48 hours. Now the OMAD focuses on both at the same time, maximizing the first and minimizing the second: it comes with a fairly long fasting time followed by a very tight window of eating.

Given that, on OMAD you are expected to see the benefits of fasting almost instantly. This is only natural: on this fasting routine you, well, basically fast all day long; your eating times are almost negligible. These extreme measures purportedly bring the following results:

  • • First, longer and more frequent fasting windows mean prolonged periods of increased autophagy.
  • • Second to that, your insulin levels may spike only once a day and for a fairly short time (usually, around one hour), meaning your endocrine system is at ease. (which, in theory, is what connects fasting with both improved cardiovascular health and easing of diseases such as type II diabetes or various autoimmune disorders). It also means decreased risk of diabetes-like symptoms and other diseases that are directly related to diet and body metabolism overall in a healthy population.
  • • Being unable to ingest too much food at once you naturally restrict your daily calories. This, together with the activation of metabolism provided by fasting and, ideally, combined with healthy regime of exercising and smart selection of food, might bring you the ultimate solution for weight loss. In fact, it might be the fastest way to shed some pounds we are aware of.

Over and above those, you get all the benefits of the IF, which you might find discussed here

Benefits of OMAD

If you are a more advanced user or work with a professional dietitian on creating your personal fasting schedule, you know that there are two main variables to consider: the duration of the fast and the length of eating window. Normally, IF regimes focus on the former: lighter versions make fasting windows shorter, and the most extreme versions have them as long as 48 hours. Now the OMAD focuses on both at the same time, maximizing the first and minimizing the second: it comes with a fairly long fasting time followed by a very tight window of eating.

Given that, on OMAD you are expected to see the benefits of fasting almost instantly. This is only natural: on this fasting routine you, well, basically fast all day long; your eating times are almost negligible. These extreme measures purportedly bring the following results:

  • • First, longer and more frequent fasting windows mean prolonged periods of increased autophagy.
  • • Second to that, your insulin levels may spike only once a day and for a fairly short time (usually, around one hour), meaning your endocrine system is at ease. (which, in theory, is what connects fasting with both improved cardiovascular health and easing of diseases such as type II diabetes or various autoimmune disorders). It also means decreased risk of diabetes-like symptoms and other diseases that are directly related to diet and body metabolism overall in a healthy population.
  • • Being unable to ingest too much food at once you naturally restrict your daily calories. This, together with the activation of metabolism provided by fasting and, ideally, combined with healthy regime of exercising and smart selection of food, might bring you the ultimate solution for weight loss. In fact, it might be the fastest way to shed some pounds we are aware of.

Over and above those, you get all the benefits of the IF, which you might find discussed here.

Drawbacks

The theory behind is that OMAD allows you to get the benefits of IF faster and without hassle; but this, naturally, may come at a price, and there are groups that should think twice before trying it.

Some of the obvious risks are the adaptation hardships, including shakiness, weakness, fatigue, irritability and inability to focus, especially if you are younger due to increased caloric requirements. But it comes with serious health risks for those suffering from hypoglycemia, as the long fasting windows might drop blood sugar to dangerous levels. It is also dangerous to people with existing eating disorders, such as anorexia and bulimia. It might even get you to develop one, called binge eating disorder.

Now while you’ve probably heard about OMAD and keto combination it is necessary to consult with a professional physician beforehand while this comes with serious risks. OMAD is extreme enough on its own and should not be combined with other diet regimes, at least not without dietitian’s advice: there is at least one case of a man who started doing OMAD together with ketogenic diet only to develop a serious case of blood acidosis. Due to extreme ketogenic diet may add up the acidic ketone bodies to a dangerous level in your bloodstream.

OMAD can be very dangerous for weight loss in diabetic patients who are taking oral hypoglycemics or insulin therapy for treatment. Ironically, hypoglycemia is the most common acute complication in patients with diabetes mellitus because of medication along with a skipped meal. So, you must consult the physician in such a scenario before starting OMAD.

Another question is that of prolonged periods of autophagy. Whether this is actually desirable is not a simple question. Autophagy is clearly a double-edged sword and can be, depending on the context, both good and bad. It may improve condition on certain bacterial infections, such as streptococcus, but worsen symptoms on others, e.g., brucella; help against the formation of tumors; but in cases of established tumors it also protects tumor cells while on chemotherapy. Even some tumors depend upon autophagy for survival and growth. It may help against certain pathways of automated cell death, but it may also support cell death in other scenarios.

Last, but certainly not least, you have to become smart about your meals. While in theory, you can abstain from thinking what to eat and just go with what you crave (OMAD alone does neither recommend, nor discourage certain foods), it is quite hard to get all your daily nutrients in one sitting. You thus need to make sure you get your daily dose of vitamins and minerals, if not with food then from supplements.

Besides the aforementioned risks associated with OMAD, there is also a scarcity of scientific research on its effects. Thus, if you do not have that biohacking mindset you’d better stick with more traditional and researched versions of fasting.

How to eat during the 20 hour fast?

If you are still tempted by OMAD, there are certain things you need to know. First, quite obviously you need to select the hour of the day that you’ll be dedicating to eating. Choose it smart and don’t be afraid to adjust it once you start your OMAD journey. Are you exercising? It might be a good idea to eat your meal an hour or so after sports to replenish your energy stores. Do you need food to be able to function and do your job duties? Eat in the morning.

As already mentioned, don’t go too harsh on yourself at once. If you’re deciding on trying OMAD together with restriction of carbohydrates or even going full-blooded keto, do it in small steps and listen to your body, or even better to discuss it with your family doctor or nutritionist. There are also psychological aspects of sticking to a diet: if you go too hard you might lose your will in the first couple of days or even cheat the same day only to feel bad about yourself. Thus you might consider starting with some of the traditional routines, such as 16:8, and then building up yourself towards OMAD.

You should also know that on your fasting windows you can consume anything that is allowed by other regimes of IF. Thus, you are free to drink coffee (without milk or sugar), tea, and even bone broth, benefits of which you may find here. You should also not forget to drink enough water throughout the day, especially if you tend to drink water together with your meals.

Finally, any diet is bad for you if it is a short-term commitment. Thus you must arrange OMAD to work for you as much trouble-free as possible. The right question to ask is this: would it be OK for me to eat like this for at least the rest of the year? If your answer is ‘no’ OMAD is probably not for you.

OMAD meal example

As it was already discussed, going one meal a day means that you have to get all your daily nutrients in one sit. Since you probably don’t want to overeat, you need to take in more concentrated food. The following is an example of what your OMAD meal might look like.

Oven-baked Camembert with salmon salad:

  • 1. Oven bake one piece of camembert (250g)
  • 2. Cook a cup of quinoa seeds. Serve with camembert on top.
  • Prepare the salad:
  • 3. Take 300 grams of raw pink salmon. Steam it to the desired level.
  • 4. Let it cool a little. Wash 100 grams of baby spinach leaves and mix it with 100 grams of dried pumpkin seeds and 100 grams of sunflower seeds.
  • 5. Add salt as desired. Put one teaspoon of extra virgin olive oil.
  • 6. Put one sliced avocado and the prepared salmon on top.
  • 7. Optionally, slice one red onion and add it to the bowl.
  • 8. Put one cup of cherry tomatoes (you might grill them if desired) and spray some balsamic vinegar
  • 9. Take two medium-boiled eggs, slice and put at the side of the salad bowl.

Eat together with one slice of wholemeal rye German bread. Enjoy! The meal consists of 1400 calories, is low-carb, and consists of at least 100% of all your daily recommended vitamins and minerals.

It just got easier to lose weight

Your personal fasting assistant

Find out what works for you with this 60-sec quiz approved by our experts and get your personal revolutionary fasting assistant

Select your gender:

MALE FEMALE

Bottom Line

OMAD is an extreme version of IF which might bring your desired results faster. It is hassle-free and lets you save time on eating meals. However, it might be harder to begin with than other types of intermittent fasting and requires more willpower to stick to. It also requires to be smart about your meal choices and requires additional attention if combined with other dietary regimes, such as keto.