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.
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:
Over and above those, you get all the benefits of the IF, which you might find discussed here.
OMAD is at its heart very straightforward to follow. One doesn’t need to count calories, eat specific foods or take any supplements. The one daily meal does not need to be consumed at any specific time of day; you may choose your own hours at the beginning of the diet. True, once chosen you might need to stick with those, since on most versions one has to maintain 23:1 regime, but the simplest version of it does not even force you to do that: you simply eat once a day and that’s it, although the former version is more beneficial. One dedicated eating break a day saves you both time and hassle spent on thinking what to eat, what products to buy, or money in case you decide to eat out. Thus, in some respects, it is the most accessible version of fasting around.
But on the other hand, eating only once a day might be hard to get used to. Long fasting windows might give you hunger pangs and headaches due to hypoglycemic effects, and you might need to skip those parties and family dinners (unless they happen to coincide with your short eating windows). You might as well start the OMAD with your habitual portion sizes giving you some serious calorie deficit, which might leave you drowsy, fatigued and dispirited: being a concentrated version of intermittent fasting it takes your body by storm and gives it a harder time to adapt. Finally, while it is a great regime for an intense month or so, in the long run, it tends to be too restrictive and hardly sustainable.
Thus, OMAD is both simple AND hard to follow. While sometimes dubbed “the lazy people fasting” it is certainly not effortless. It is simplistic in its structure, but brings some serious effort to follow and maintain.
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.
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.
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:
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.
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.
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