11 myths about intermittent fasting and meal frequency

Intermittent fasting has become hugely popular in recent years. This is a dietary pattern that alternates cyclically between phases of eating and fasting. However, there are still a lot of myths surrounding this topic. This article debunks the 11 most common myths about fasting, snacking and meal frequency.

1. skipping breakfast will make you fat

"Breakfast is the most important meal of the day." There is still this myth that says breakfast is special. People believe that skipping breakfast will lead to excessive hunger, cravings and weight gain.

However, although observational studies have found a statistically significant link between skipping breakfast and obesity, this link could be explained by the fact that the stereotypical 'breakfast skipper' is less health conscious overall.

Interestingly, this question was recently clarified by a randomized clinical trial that met the gold standard of scientific studies. This study was published in 2014 and compared the effects of eating breakfast versus skipping breakfast in 283 overweight and obese adults(https://www.ncbi.nlm.nih.gov/pubmed/24898236). At the end of the 16-week study phase, no difference was observed between the groups.

This study shows that it makes no difference to weight loss whether you eat breakfast or not, although there may be individual differences.

However, there are some studies that show that children and teenagers who eat breakfast tend to perform better at school.(https://www.sciencedirect.com/science/article/pii/S0002822305001513)

There are also studies of people who had long-term weight loss that show that these people tend to eat breakfast(https://www.ncbi.nlm.nih.gov/pubmed/16002825).

This is one of those things that can vary from person to person. Breakfast is beneficial for some people and not for others. However, it is certainly not essential and there is nothing magical about this meal.

Conclusion: Eating breakfast may be beneficial for some people, but it is not essential. Controlled studies show no difference between eating breakfast and not eating breakfast when it comes to weight loss.

2. eating more frequently increases the metabolic rate

"Eat small meals to keep the metabolic flame burning." Many people believe that eating many smaller meals leads to an increased metabolic rate, so that your body burns more calories overall.

It is true that the body uses a certain amount of energy to digest and absorb the nutrients from a meal. This is also known as the thermic effect of food, which accounts for 20 to 30% of the calories consumed for protein, 5 to 10% for carbohydrates and 0 to 3% for fat.

On average, the thermic effect of food is somewhere in the region of 10% of the total calorie intake.

However, the only thing that matters here is the total amount of calories consumed - not the number of meals you eat.

Eating six meals of 500 kcal each has exactly the same effect as eating one meal of 1000 kcal each. Assuming an average thermal effect of 10%, this corresponds to 300 kcal in both scenarios.

This is supported by numerous human studies which show that increasing or decreasing the frequency of meals has no effect on the total amount of calories burned(https://www.ncbi.nlm.nih.gov/pubmed/9155494).

Conclusion: It makes no difference to the calories burned whether you eat more frequently or not. Only the total calorie intake and the distribution of macronutrients play a role.

3. more frequent meals help to reduce hunger

Some people believe that snacking helps prevent cravings and excessive hunger. Interestingly, several studies have looked at this issue and the results are mixed.

Although some studies suggest that more frequent meals lead to reduced hunger, other studies have found no effect, while still other studies have concluded that more frequent meals can actually increase hunger(https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/acute-effects-on-metabolism-and-appetite-profile-of-one-meal-difference-in-the-lower-range-of-meal-frequency/4AE8C3FC32CE7E456B9606F1AF963E76, https://www.sciencedirect.com/science/article/pii/S0195666399902659, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0038632, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4391809/)

One study that compared 3 high-protein meals with 6 high-protein meals concluded that 3 meals were even better for reducing hunger(https://www.ncbi.nlm.nih.gov/pubmed/20339363).

So it seems to depend on the individual which meal frequency is better. If snacks between meals help you feel less cravings and reduce your risk of binge eating, then they are a good thing.

However, there is no evidence that snacks or more frequent meals reduce hunger for everyone. So different approaches may be best for different people.

Conclusion: There is no consistent evidence that eating more frequently reduces hunger or calorie intake. Some studies even show that more frequent meals increase hunger.

4. many smaller meals can help you lose weight

More frequent meals do not additionally stimulate the metabolic rate (i.e. there is no increase in calorie consumption). They also don't seem to reduce hunger (which means there is no reduction in food intake).

If more frequent meals have no effect on the energy balance equation, then they should also have no effect on weight loss.

In fact, this is also supported by science. Most studies conducted on this topic show that meal frequency has no effect on weight loss(https://www.ncbi.nlm.nih.gov/pubmed/26024494, https://www.ncbi.nlm.nih.gov/pubmed/26226640)

For example, a study of 16 overweight men and women found no difference in weight, fat loss or appetite when 3 daily meals were compared to 6 daily meals(https://www.ncbi.nlm.nih.gov/pubmed/19943985).

However, if you feel that you find it easier to eat less and consume less junk food when you eat more often, then this strategy could be effective for you.

Personally, I find it damn inconvenient to eat so often and it makes it even harder for me to stick to a healthy diet, but it might work for other people.

Conclusion: There is no evidence that changing your meal frequency will help you lose more weight. Most studies show that it makes no difference.

5. the brain needs a constant supply of glucose

Some people believe that their brain will stop functioning if they don't eat carbohydrates every few hours. This is based on the belief that our brain can only use glucose (in the form of blood sugar) as an energy source.

However, what is often overlooked is the fact that the body can easily produce the glucose it needs itself through a process called gluconeogenesis(https://www.ncbi.nlm.nih.gov/pubmed/19640952). However, in most cases this will not be necessary as the body stores glucose in the liver in the form of glycogen, which it can use to fuel the brain for many hours.

Even during long-term fasting or a very low-carbohydrate diet, the body can produce so-called keto bodies from dietary fats(https://www.ncbi.nlm.nih.gov/pubmed/19227486). Ketobodies can cover part of the brain's energy requirements and thus significantly reduce the need for glucose.

During a prolonged fast, the brain can therefore easily be supplied with sufficient amounts of energy by ketobodies and glucose, which is produced from proteins.

It also makes no sense from an evolutionary point of view that we should not be able to survive without a constant supply of carbohydrates. If this were the case, mankind would have died out a long time ago.

However, some people report a feeling of low blood sugar if they don't eat for a while. If this applies to you, then you may want to stick to a higher meal frequency or talk to your doctor before changing your diet.

Conclusion: The body can produce glucose itself to provide the brain with energy during longer periods of fasting. Part of the brain can also use keto bodies as an energy source.

6. eating often and snacking between meals is good for your health

It is simply not "natural" for the body to be in a state of continuous food intake. Throughout human evolution, mankind has had to endure periods of starvation.

There is also evidence that short-term fasting initiates a process of cellular repair known as autophagy, in which old and dysfunctional proteins are used as a source of energy(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106288/).

The process of autophagy could counteract the ageing process and reduce the risk of numerous diseases including Alzheimer's(https://www.ncbi.nlm.nih.gov/pubmed/23773064, https://www.ncbi.nlm.nih.gov/pubmed/19524509). The fact is that fasting from time to time has all sorts of benefits for metabolic health(https://www.sciencedirect.com/science/article/pii/S193152441400200X, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946160/, https://ibimapublishing.com/articles/ENDO/2014/459119/).

There are also some studies that suggest that frequent snacking and eating may have negative effects on health and increase the risk of certain diseases.

For example, one study found that a diet with more frequent food intake combined with a high calorie intake may cause greater exacerbation of a fatty liver condition, suggesting that more frequent snacking may increase the risk of fatty liver(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4265261/).

There are also some observational studies showing that people who eat more often are at higher risk of malignant tumors in the gut(http://cancerres.aacrjournals.org/content/52/13/3589.short, https://link.springer.com/article/10.1007%2FBF00051916).

Conclusion: It is a myth that frequent snacking is inherently good for your health. Some studies show that frequent snacking is harmful, while other studies show that occasional fasting can have significant health benefits.

7. fasting puts your body into starvation mode

A common argument against intermittent fasting is that it can put the body into a so-called starvation mode. According to these claims, fasting tricks your body into thinking it's starving, causing it to reduce your metabolic rate and prevent you from burning fat.

It's actually true that long-term weight loss can reduce the amount of calories you burn. This is the true "starvation mode" (the technical term for this is adaptive thermogenesis)(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673773/).

This is a real effect that adds up to a few hundred fewer calories burned per day. However, this happens during weight loss regardless of the method used. There is no evidence that this happens more often or to a greater extent with intermittent fasting than with other weight loss methods.

In fact, there is even evidence that short-term fasting can actually increase the metabolic rate. This is related to a dramatic increase in norepinephrine (noradrenaline) blood levels, which signals fat cells to break down body fat and stimulate metabolism(https://www.ncbi.nlm.nih.gov/pubmed/12107252, https://www.ncbi.nlm.nih.gov/pubmed/10837292).

Studies have shown that fasting for up to 48 hours can increase the metabolic rate by 3.6 to 14%(https://www.ncbi.nlm.nih.gov/pubmed/2405717). However, if you fast for significantly longer, this effect can be reversed and the metabolic rate can fall below the baseline value(https://www.ncbi.nlm.nih.gov/pubmed/3661473).

One study showed that fasting every other day for 22 days did not lead to a reduction in metabolic rate, while at the same time the subjects lost 4% of their fat mass, which is an impressive figure for such a short phase of only 3 weeks(https://www.ncbi.nlm.nih.gov/pubmed/15640462).

Conclusion: It is false that short-term fasting puts the body into "starvation mode". The truth is that the metabolic rate actually increases during the first 48 hours of fasting.

8. the body can only use a certain amount of protein per meal

There are some who claim that we can only digest 30 grams of protein per meal and therefore should eat every 2 to 3 hours to maximize our muscle gains. However, these claims are not supported by science.

Studies show no difference in muscle mass if you split your protein intake into more frequent smaller portions(https://www.ncbi.nlm.nih.gov/pubmed/17413096, https://www.ncbi.nlm.nih.gov/pubmed/10867039, https://www.ncbi.nlm.nih.gov/pubmed/10357740).

The most important factor for most people is the total amount of protein consumed, not how many meals that protein was divided into.

Conclusion: The body can easily use more than 30 grams of protein per meal and it is not necessary to consume protein every 2 to 3 hours.

9 Intermittent fasting makes you lose muscle

Some people believe that our body will start to burn muscle and use muscle protein for energy. It is true that this generally happens during dieting, but there is no evidence that this happens to a greater extent with intermittent fasting than with other diets.

Some studies even suggest that intermittent fasting is better for maintaining muscle mass. In one meta-study, phased calorie restriction resulted in similar weight loss to continuous calorie restriction, but less muscle mass was lost(https://www.ncbi.nlm.nih.gov/pubmed/21410865).

There is also a study in which subjects ate the same amount of calories as normal, but consumed them in the form of a large meal in the evening(https://www.ncbi.nlm.nih.gov/pubmed/17413096). These subjects lost body fat and showed a minimal (almost statistically significant) increase in muscle mass combined with a number of positive effects on other health markers.

Intermittent fasting is also popular with many bodybuilders who see this form of nutrition as an effective way to maintain large amounts of muscle mass in combination with a low body fat percentage.

Conclusion: There is no evidence that fasting causes greater muscle loss than conventional calorie restriction. In fact, some studies show that intermittent fasting may be helpful in maintaining existing muscle mass while dieting.

10. intermittent fasting is bad for your health

Some people believe that fasting can be unhealthy, but nothing could be further from the truth. Numerous studies show that intermittent fasting and intermittent calorie restriction can have amazing health benefits(https://www.sciencedirect.com/science/article/pii/S193152441400200X, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946160/, https://ibimapublishing.com/articles/ENDO/2014/459119/).

For example, intermittent fasting alters the expression of certain genes associated with longevity and protection against certain diseases, and intermittent fasting has been shown to increase lifespan in experimental animals(https://www.ncbi.nlm.nih.gov/pubmed/24048020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2622429/, https://academic.oup.com/geronj/article-abstract/38/1/36/570019, https://www.sciencedirect.com/science/article/pii/S0047637400001093, https://www.karger.com/Article/Abstract/212538).

It also has clear benefits for metabolic health, including improved insulin sensitivity, reduced oxidative stress, reduced inflammatory markers and a reduction in risk factors for heart disease(https://www.sciencedirect.com/science/article/pii/S193152441400200X, https://ibimapublishing.com/articles/ENDO/2014/459119/, https://www.sciencedirect.com/science/article/pii/S095528630400261X, https://www.ncbi.nlm.nih.gov/pubmed/17291990/).

Intermittent fasting may also be good for the brain, as it can increase levels of a brain hormone called brain-derived neurotrophic factor (BDNF). This could protect against depression and numerous other brain problems(https://www.ncbi.nlm.nih.gov/pubmed/16011467, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC151440/, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3022308/).

Conclusion: Some people think that fasting is harmful, but the exact opposite is true. Short-term fasting has clear benefits for the body and brain.

11. intermittent fasting makes you eat too much

Some claim that intermittent fasting will not result in weight loss because it causes you to overeat during the eating window. This is partly true. After a period of fasting, people automatically tend to eat a little more than if they had not fasted. In other words, they compensate for the calories "lost" during the fast by eating more during the next meals.

However, this compensation is not complete. One study showed that people who fasted for a whole day only ate 500 extra kcal the next day(https://www.ncbi.nlm.nih.gov/pubmed/12461679). They saved about 2400 kcal on the fasting day and ate only 500 kcal more the following day, which corresponded to a total calorie reduction of 1900 kcal, which is a very high calorie deficit for only 2 days.

Intermittent fasting reduces total food intake while stimulating the metabolism. It also reduces insulin levels, increases norepinephrine levels and increases growth hormone secretion by up to five times(https://www.ncbi.nlm.nih.gov/pubmed/10837292, https://www.ncbi.nlm.nih.gov/pubmed/15640462, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/, https://www.ncbi.nlm.nih.gov/pubmed/1548337).

Because of these factors, intermittent fasting will make you lose fat, not gain it. According to a 2014 meta-study, fasting for 3 to 24 weeks resulted in a weight loss of 3 to 8% and a reduction in abdominal fat of 4 to 7%(https://www.sciencedirect.com/science/article/pii/S193152441400200X).

In this study, intermittent fasting resulted in a weight loss of 0.5 pounds per week, while fasting every other day resulted in a weight loss of 1.6 pounds per week.

The truth is that intermittent fasting is one of the most effective tools for fat loss. To say that it will make you eat more, put you in starvation mode and result in weight gain is the exact opposite of reality.

Source: https://www.healthline.com/nutrition/11-myths-fasting-and-meal-frequency#section1