In the world of nutrition, one of the most common recommendations is the need to “eat every 3 hours”. This advice is given for a number of reasons, which I will mention below.

However … what if I told you this was all a lie ?

And I’m not talking about just one reason: in this article I’m going to present the top 4 reasons cited by people (even nutritionists and otherwise brilliant health professionals) that go against this recommendation.

In addition to presenting these supposed “reasons”, I will bring the scientific evidence  that shows that each one is wrong.

This will prove that the instructions to eat every 3 hours is nothing more than a long-propagated myth.

Note: Many readers have asked for scientific references (which is good! It shows that people are becoming more and more interested in their health) – especially in controversial articles

So without further ado let’s explore those myths!

Myth # 1 – Eating Every 3 Hours Accelerates Metabolism

Eating Every 3 Hours Accelerates Metabolism

The origin of the myth:

Each time you eat, for a few hours, your metabolism gets a little faster.

This is because the process of digestion and absorption of nutrients from food needs energy to happen.

We call this the Thermic Effect of Food. So the reasoning behind this myth is this: if, every time I eat, my metabolism goes up, I just need to eat more often to make my metabolism faster, right?


Wrong because this reasoning ignores an important fact: the elevation of metabolism from food is proportional to the amount of calories and nutrients ingested .

Or, using an example to explain:

Imagine that I wanted to measure the Thermic Effect of Food for a period of 24 hours, given that the diet is the same. In this case, I will consider a 3000 kcal diet, composed of 40% protein, 40% carbohydrates, and 20% fat – but in two different scenarios.

In the first, I divided this food into 3 meals of 1000 kcal while, in the second, I divided throughout the day into 6 meals of 500 kcal. How is the thermal effect in this case?

Eating every 3 hours
The image above illustrates this concept well:

And in it you can see that the orange chart has 6 peaks (representing eating frequently), while the green (representing eating less frequently) only three …

However, these three green peaks are higher than the orange peaks, so that the average value of both lines is equal .

In addition to charting, I also separated this extensive review of studies published in 1997 that examined various eating frequencies – only to prove that there are in fact no calorie expenditure advantages in distributing more meals during the day.

It is worth mentioning that since the publication of this study (already good 18 years ago) no other study has refuted it.

In addition, Lyle McDonald – author of some good books, such as Stubborn Body Fat Solution (whose stubborn fat burning protocols we present here ), also made some very interesting comments about the study quoted above – see them here .

And just to complete, in 2010 another study was published  and guess what: no differences were found between fewer (3) or more (6) meals a day.

The good part of this study is that it has garnered some attention from the mass media, even turning it into an article in the New York Times .

That is: if the reason for eating every 3 hours was the elevation of metabolism, this argument has long since gone downhill.

Myth # 2 – Eating Less More Often Controls Hunger

 Eating Less More Often Controls Hunger

The origin of the myth:

The truth is there is very little research in this regard to foods that control hunger.

One of the few available  has the following arrangement:

Some obese men were selected and they fed them with 33% of their daily calorie requirement in one of two ways:

  • beginning with a single meal, and 5 hours later they could eat whatever they wanted;
  • or in 5 small meals, one every hour, and then they would eat whatever they wanted.

In the results, it was observed that the members of the first group ate 27% more calories in the meal where they could eat what they wanted.

The same researchers did a study this time with men in shape, and obtained similar results .

Ah … so this proves that smaller and more frequent meals actually decrease appetite, right?


The results show that for that macronutrient composition , smaller and more frequent meals actually decrease appetite, compared to a single meal and a 5-hour fast.

The problem with this is that the feed composition used in the study makes no sense in the real world – especially in a diet setting.

The meal consisted of 70% carbohydrates, 15% fats and 15% protein; they were providing foods such as noodles, ice cream and orange juice (!).

Eating every 3 hours,

What do you think of the glycemic index of  this meal? Would you eat a diet based solely on these foods?

In contrast, another study, more recent  with more realistic conditions , was made , and guess what: it shows the opposite.

In it, three meals with high protein content provoked more satiety and less hunger than six meals of the same composition.

Bare in mind that any weight loss plan is greatly facilitated by a diet rich in proteins and fats and less carbohydrates.

This helps induce ketosis and allows for ingestion of macronutrients which provide satiety.

So the conditions of the second study are much closer to real-life eating than to that of the first. I mean, who eats ice cream and orange juice every hour on a diet to lose weight ?!

Still, I want to make our recommendations clear: the preferred eating frequency varies from person to person.

What I want to deny is absolute information like “to control appetite, it’s always better to eat small meals more frequently than large meals less frequently.”

Being that a study, like the one mentioned above, tramples this type of illusion and “absolute truth”.

I will consider this another myth destroyed.

Myth # 3 – Eating Every 3 Hours Helps Keep Glycemia Under Control

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The origin of the myth:

Good question!

Except in people with a relatively high levels of insulin resistance , there should be no effect associated with hypoglycemia caused by fasting for adequate duration.  

But I always get hypoglycemia when I have not eaten for some time, so that statement must be true, right?


If we feel any negative effects with this type of fast, it is precisely because our body has become accustomed to frequent meals and is in a state of constant glycolysis.

Contrary to what many seem to believe, the body has extremely robust control mechanisms for important variables of our health – including blood sugar levels.

To facilitate understanding, think for a second of our ancestors.

Do you think they ate every 3 hours?

paleo, diet, paleolithic, slimming, health, low-carb

Periods of fasting and food shortage were constant, if they were unable to act efficiently-and I mean with mind and body-where do you think we would be today?

And let’s think about a somewhat more extreme scenario:

What do you think would happen if you were fasting for 23 hours and then running for 90 minutes?

How would your blood glucose levels compare with someone who ate normally and then ran?

Fortunately, we do not have to imagine much: because this study shows that they would probably be the same .

(Of course there are other consequences, such as lactate elevation, and increased use of fats when fasting – but the glycemia, which is the point of contention in this myth, remained the same.)

And another bonus study for you: now showing that a 48- hour fast did not bring any decline in the cognitive ability of the people tested.

Yes, forty-eight hours .

On the other hand, there are other factors that influence the regulation of appetite, such as your usual diet, your exercise routine, and even your genetics.

Still, it is no less important to consider your own usual frequency of feeding, because there is a direct relationship between hormones and hormones – such as ghrelin .

Basically, the implication is that your blood glucose accompanies the times you are accustomed to eating – and because of this, you are hungry at times out of habit.

To illustrate, consider the following situation.

Suppose you were accustomed to lunch, say, at 2:00 pm every day, and suddenly your routine changes (for example, you change jobs) and from now on you have to eat at noon.

In the early days, you wouldn’t have felt hungry at these time.

But after a few weeks, you will have become accustomed to eating at noon.

So much so, that when you get 11:50, you’ll literally be salivating with hunger! It is a simple example, but it serves well to illustrate the point.

And this is relevant because it means that people can quickly adapt to new eating patterns without feeling any negative effect …

… Including eating less meals.

Myth # 4 – If I Do not Eat Every 3 Hours I’ll Catabolize and Destroy Muscle Mass

eat every 3 hours, eat every 3 hours, eat every 3 hours Myth or truth, metabolism, myth, truth, lie, eat every three hours

The origin of the myth:

The truth is people love to over exaggerate.

In this case, this is based on a simple fact: if you stay many hours without eating, you will burn muscles as a source of energy.

So I shouldn’t stay over 3 hours without eating, because my body will destroy all the muscles that I sweated so hard to get … right?


The fact is if you stay in prolonged periods of time without eating, your body will use muscle as a form of energy ( in a process called “gluconeogenesis” ). This is a fact.

However, the distortion refers to what would be “extended periods of time”.

While some so-called experts consider 3 or 4 hours as an extended period, studies indicate that this time window is much wider at 16 to 28 hours – that is, if muscle glycogen has already been depleted before.

Let’s say you had to stay 16 to 28 hours without eating, after training, that’s a significant part of the energy consumed coming from muscle tissue (significant part = 50% in the case of 16 hours and 100% in the case of 28 hours).

Of course, I wouldn’t recommend anyone staying 28 hours without eating after an intense workout …

On the other hand, ingesting a few grams of BCAA just before training can counterbalance any losses that might occur while training in a fasting state.

As a counterpoint, an interesting study  (the summary of which can be seen here ) was published in the American Journal of Clinical Nutrition in 2007 in which completely normal people (healthy, normal-weight, and middle-aged) were arranged in two distinct arrangements.

In one, they ate one meal a day (23-hour fasting daily); while in the other they ate 3 meals a day for 8 weeks.

Surprisingly for some, the individuals in the first group went through a significant body recomposition, including drastically reducing their percentage of body fat, without loss of lean mass (actually, with a subtle gain of muscle mass ) … and all with the same intake calorie – just eating less often!

(Still, I feel obliged to leave as a caveat that the measurement was performed by bioimpedance, a method that is notably prone to inaccuracies).

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In short, the lesson here is:  eating every 3 hours will not improve your muscle mass gains, let alone avoid catabolism .

Do not fall for this charade.

I want to emphasize that you should only when you are hungry, without sticking to a time table.

If you are hungry every 3 hours, eat every 3 hours. If you are not hungry then, don’t eat. Simple.

In fact, many people go in the opposite direction to have results: intermittent fasting – read more here.

But then … if all this is true, why does the fallacy about the need to eat every 3 hours continue to be propagated?

This question is not trivial. But we can imagine 3 main reasons:

# 1 – Repetition

eat every 3 hours, eat every 3 hours, eat every 3 hours Myth or truth, metabolism, myth, truth, lie, eat every three hours

a lie that is repeated a thousand times becomes truth.”

Ever heard that phrase?

Although it is unclear who is the author of this famous citation (which many believe to be Joseph Goebbels, Adolf Hitler’s Propaganda Minister in Nazi Germany), the fact is that people tend to believe in things they hear often enough.

In addition, the fact that bodybuilders and fitness celebrities often propagate this myth creates a greater acceptance bias – after all, people tend to think that, “if these people, who are in shape do this, then it should work “.

In response I suggest you read this quote from Dr. Jose Carlos, author of the blog Low Carb Diet Paleolithic :

People who are genetically lean and / or strong convince others that this is due to the method they are trying to sell, rather than just winning at the genetic lottery”

Many fitness celebrities (especially those who have never gone through the other extreme – that is, of being fat) simply don’t recognize the kind of emotional ties to food many of their readers feel. For example, Junk food day, which I speak about here, increases the chances of success in any diet.

# 2 – Financial Interests

eat every 3 hours, eat every 3 hours, eat every 3 hours Myth or truth, metabolism, myth, truth, lie, eat every three hours

For most people, it is not practical to eat every 3 hours.

Especially if these people are trying to get rid of a few extra pounds, so they focus on buying healthy snacks …

And guess who wins with that?

Exactly: companies that manufacture supplements, cereal bars, protein bars, wholemeal cookies, and more.

After all, what market would they have if everyone discovered that they only need to eat when they are hungry, without following a predefined time on the clock?

There is no commercial and financial incentive to tell people they would be okay with one main meal a day.

# 3 – Knowledge

eating every 3 hours

It is controversial to disagree with the pillars of so-called “mass nutrition”. However, their “diet facts” are disseminated into publications without any true scientific references. However, it’s this type of reading most consumed by lay people who are sincerely interested in living more healthily.

They are magazines, websites, even nutritionists (which I believe are well-intentioned, but have pushed concepts like this) – their usual recommendation is to eat every 3 hours.

Let’s cut to the chase: a lay person is probably never going to have access to the studies we have just seen, where they blast this old myth out of the water.

At the same time, there are some excellent professionals who debunk the outdated idea of ​​eating every 3 hours.

But they’re dietary knowledge is not widely spread.

It’s a pity.

But I hope to do my part to inform an increasing number of people about the facts. That way people can make the right choices for their lives, so they can eat only when they want to eat. =)

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