OMAD is a popular term thrown around amongst those interested in ‘hacking’ longevity, improving metabolic flexibility and losing weight. Many people report feeling better on OMAD, but what exactly is it and how does it work?

What Is OMAD?

OMAD stands for ‘one meal a day’. Yes, just one meal a day. It sounds crazy, but this isn’t just one normal-sized meal. This tends to be a supersized meal consisting of a minimum of 1,200 calories and perhaps even up to 3,000 calories depending on what foods are eaten.

Whilst it sounds like it may be the start of an eating disorder, the truth is, OMAD and various types of intermittent fasting probably mimic the way we used to eat as hunter-gatherers. Food wasn’t always available which meant that eating was a more ‘irregular’ occurrence and we wouldn’t always have the leisure of being able to eat three square meals a day. Personally, I wouldn’t class OMAD or any type of intermittent fasting as a diet, but rather as a lifestyle or way of eating which can be tweaked to fit any individual.

Some do OMAD by eating any food they want within the space of one hour whilst others will fill up a big plate and not eat more than what’s on their plate. You could also simply eat to satiety for that one meal and not eat for the rest of the day until the following day.

Why Do OMAD?

The reasons people choose to do OMAD vary. Some will do it every day as long as it’s feasible whilst others will do it on a more semi-regular basis such as on weekends whilst keeping eating during weekdays more regular or at two meals a day.

#1 – Less Worrying About Food

With OMAD you only eat once during the day so you don’t need to worry about hunger pangs, snacks or what you’re going to eat for breakfast, lunch or dinner. You only need to focus on one meal and make it big. Even people eating junk food or a high-carb diet that follow this protocol will find that they can lose weight without giving up their favourite foods as long as they can stick to the ‘one meal a day’ focus of OMAD (as it states in the name) because of the satiety that eating such a large meal induces.

#2 – Improved Fat Burning

Where glucose is available, the body will burn glucose. However, in the absence of glucose, your body will burn fat in the bloodstream (dietary fat) before moving onto stored body fat. For most of us, after eating meals on such a regular basis with most of them focused around carbohydrates, our bodies forget how to burn fat.

When you do OMAD and don’t eat for 22+ hours then glucose which is readily available will soon be depleted which means your body has to learn to burn body fat more efficiently. If you exercise fasted in this state, this effect is further increased by forcing your body to release energy from fat more readily in order to keep up with the demands of your exercise.

#3 – Increased Insulin Sensitivity

Without constant meals, your body is getting a lot less insulin signalling from food. This means that when you next eat, your cells will be increasingly sensitive to insulin which means that when you next eat your body will be very effective at obtaining nutrients from your food. This will cause a great insulin spike, but this is fine since it’s only happening once or twice during your eating window with OMAD. Those who have insulin problems will find that they arise for spiking insulin too much and too often which is usually from eating frequently and eating foods with a high food insulin index.

Diabetics and prediabetics have a state of insulin resistance which makes it hard to regulate insulin. One doctor, Dr Jason Fung has found that he is able to reverse diabetes and the need for insulin medication by using intermittent fasting and a low carb diet. OMAD is a type of intermittent fasting which can help to reduce insulin resistance and improve insulin sensitivity within the cells.

#4 – Enhanced Satiety And Reduced Hunger

Surprisingly, eating such a large meal, like a roast Christmas dinner, can make you feel very full and cause you to eat fewer calories than if you ate three meals plus snacks throughout the day. OMAD can help to enhance satiety and reduce hunger so that you’ll think less about food throughout the day and be able to focus more on other activities such as work, exercise and family.

#5 – Increased Appetite

For some, the increased appetite that OMAD brings the following day is a good reason to do it. Hunger is the best spice. When you’re hungry, almost anything tastes good. Well, let’s say anything edibleFood. It makes that one meal of the day more enjoyable. We’re not talking about pushing yourself to borderline starvation, but just to the point where you have an appreciable level of hunger build up.

#6 – Improved Cognitive Function

Many find that whilst fasting, cognitive function is improved. A study performed on mice found that learning and memory were improved when intermittent fasting using alternate-day fasting. There are many more anecdotes out there suggesting that focus is also increased, but if you’re hungry to the point you can’t focus then this evidently is not the case.

#7 – Autophagy Benefits

Autophagy is your body’s recycling system where cells remove damaged molecules and dysfunctional mitochondria, effectively turning off cell growth. This is due to your body trying to conserve resources since you haven’t been eating for a while. Then when you eat after having fasted for a while the cell growth switch is turned on. This helps proteins to grow and new synapses to be formed.

As a form of intermittent fasting, OMAD promotes autophagy which can make your body more resistant to stress since it stresses the body due to the absence of food.

Note On OMAD

OMAD is not for everyone. Some will feel better on OMAD whilst others may feel worse. It depends on your genetics and epigenetics. If you’ve been on a keto diet which prioritises fat burning, then you’ll probably be able to adapt to OMAD much more easily than someone following a high-carb diet.

If you’re interested in trying it out then I suggest transitioning to a low carb diet first and trying a form of intermittent fasting known as time-restricted feeding where you typically fast for 16 hours and eat during an 8 hour eating window. As always, before trying any type of intermittent fasting or diet please consult your doctor first.


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Further Reading:

Intermittent Fasting To Lose Body Fat

What Is A Low Carb Diet?