Fasting has become increasingly common.
In fact, intermittent fasting, a dietary pattern that cycles between periods of fasting and eating, is often promoted as a miracle diet.
Yet, not everything you’ve heard about meal frequency and your health is true.
Here are 11 myths about fasting and meal frequency.
1. Skipping breakfast makes you fat
One ongoing myth is that breakfast is the most important meal of the day.
People commonly believe that skipping breakfast leads to excessive hunger, cravings, and weight gain.
One 16-week study in 283 adults with overweight and obesity observed no weight difference between those who ate breakfast and those who didn’t (1 ).
Thus, breakfast doesn’t largely affect your weight, although there may be some individual variability. Some studies even suggest that people who lose weight over the long term tend to eat breakfast (2 ).
What’s more, children and teenagers who eat breakfast tend to perform better at school (3).
As such, it’s important to pay attention to your specifc needs. Breakfast is beneficial for some people, while others can skip it without any negative consequences.
SUMMARY
Breakfast can benefit many people, but it’s not essential for your health. Controlled studies do not show any difference in weight loss between those who eat breakfast and those who skip it.
2. Eating frequently boosts your metabolism
Many people believe that eating more meals increases your metabolic rate, causing your body to burn more calories overall.
Your body indeed expends some calories digesting meals. This is termed the thermic effect of food (TEF) (4 ).
On average, TEF uses around 10% of your total calorie intake.
However, what matters is the total number of calories you consume — not how many meals you eat.
Eating six 500-calorie meals has the same effect as eating three 1,000-calorie meals. Given an average TEF of 10%, you’ll burn 300 calories in both cases.
Numerous studies demonstrate that increasing or decreasing meal frequency does not affect total calories burned (5 ).
SUMMARY
Contrary to popular belief, eating smaller meals more often does not increase your metabolism.
3. Eating frequently helps reduce hunger
Some people believe that periodic eating helps prevent cravings and excessive hunger.
Yet, the evidence is mixed.
Although some studies suggest that eating more frequent meals leads to reduced hunger, other studies have found no effect or even increased hunger levels (6 , 7, 8 , 9 ).
One study that compared eating three or six high-protein meals per day found that eating three meals reduced hunger more effectively (10 ).
That said, responses may depend on the individual. If frequent eating reduces your cravings, it’s probably a good idea. Still, there’s no evidence that snacking or eating more often reduces hunger for everyone.
SUMMARY
There’s no consistent evidence that eating more often reduces overall hunger or calorie intake. Rather, some studies show that smaller, more frequent meals increase hunger.
4. Frequent meals can help you lose weight
Since eating more frequently doesn’t boost your metabolism, it likewise doesn’t have any effect on weight loss (11 , 12 ).
Indeed, a study in 16 adults with obesity compared the effects of eating 3 and 6 meals per day and found no difference in weight, fat loss, or appetite (13 ).
Some people claim that eating often makes it harder for them to adhere to a healthy diet. However, if you find that eating more often makes it easier for you to eat fewer calories and less junk food, feel free to stick with it.
SUMMARY
There’s no evidence that changing your meal frequency helps you lose weight.
5. Your brain needs a regular supply of dietary glucose
Some people claim that if you don’t eat carbs every few hours, your brain will stop functioning.
This is based on the belief that your brain can only use glucose for fuel.
However, your body can easily produce the glucose it needs via a process called gluconeogenesis (14 ).
Even during long-term fasting, starvation, or very very-low-carb diets, your body can produce ketone bodies from dietary fats (15 ).
Ketone bodies can feed parts of your brain, reducing its glucose requirement significantly.
However, some people report feeling fatigued or shaky when they don’t eat for a while. If this applies to you, you should consider keeping snacks on hand or eating more frequently.
SUMMARY
Your body can produce glucose on its own to fuel your brain, meaning that you don’t need a constant dietary glucose intake.
6. Eating often is good for your health
Some people believe that incessant eating benefits your health.
However, short-term fasting induces a cellular repair process called autophagy, in which your cells use old and dysfunctional proteins for energy (16 ).
Autophagy may help protect against aging, cancer, and conditions like Alzheimer’s disease (17 , 18 ).
Thus, occasional fasting has various benefits for your metabolic health (19, 20 , 21).
Some studies even suggest that snacking or eating very often harms your health and raises your risk of disease.
For example, one study found that a high-calorie diet with numerous meals caused a substantial increase in liver fat, indicating a higher risk of fatty liver disease (22 ).
Additionally, some observational studies show that people who eat more often have a much higher risk of colorectal cancer (23 , 24).
SUMMARY
It’s a myth that snacking is inherently good for your health. Instead, fasting from time to time has major health benefits.
7. Fasting puts your body in starvation mode
One common argument against intermittent fasting is that it puts your body into starvation mode, thus shutting down your metabolism and preventing you from burning fat.
While it’s true that long-term weight loss can reduce the number of calories you burn over time, this happens no matter what weight loss method you use (25 ).
There’s no evidence that intermittent fasting causes a greater reduction in calories burned than other weight loss strategies.
In fact, short-term fasts may increase your metabolic rate.
This is due to a drastic increase in blood levels of norepinephrine, which stimulates your metabolism and instructs your fat cells to break down body fat (26 , 27 ).
Studies reveal that fasting for up to 48 hours can boost metabolism by 3.6–14%. However, if you fast much longer, the effects can reverse, decreasing your metabolism (27 , 28 , 29 ).
One study showed that fasting every other day for 22 days did not lead to a reduction in metabolic rate but a 4% loss of fat mass, on average (30 ).
SUMMARY
Short-term fasting does not put your body into starvation mode. Instead, your metabolism increases during fasts of up to 48 hours.
8. Your body can only use a certain amount of protein per meal
Some people claim that you can only digest 30 grams of protein per meal and that you should eat every 2–3 hours to maximize muscle gain.
However, this is not supported by science.
Studies show that eating your protein in more frequent doses does not affect muscle mass (31 , 32 , 33 ).
The most important factor for most people is the total amount of protein consumed — not the number of meals it’s spread over.
SUMMARY
Your body can easily make use of more than 30 grams of protein per meal. It’s unnecessary to obtain protein every 2–3 hours.
9. Intermittent fasting makes you lose muscle
Some people believe that when you fast, your body starts burning muscle for fuel.
Although this happens with dieting in general, no evidence suggests that it occurs more with intermittent fasting than other methods.
On the other hand, studies indicate that intermittent fasting is better for maintaining muscle mass.
In one review, intermittent fasting caused a similar amount of weight loss as continuous calorie restriction — but with much less reduction in muscle mass (34 ).
Another study showed a modest increase in muscle mass for people who consumed all their calories during one huge meal in the evening (31 ).
Notably, intermittent fasting is popular among many bodybuilders, who find that it helps maintain muscle alongside a low body fat percentage.
SUMMARY
There’s no evidence that fasting causes more muscle loss than conventional calorie restriction. In fact, studies demonstrate that intermittent fasting may help you maintain muscle mass while dieting.
10. Intermittent fasting is bad for your health
While you may have heard rumors that intermittent fasting harms your health, studies reveal that it has several impressive health benefits (19, 20 , 21).
For example, it changes your gene expression related to longevity and immunity and has been shown to prolong lifespan in animals (35 , 36 , 37 , 38, 39).
It also has major benefits for metabolic health, such as improved insulin sensitivity and reduced oxidative stress, inflammation, and heart disease risk (19, 21, 40, 41 ).
It may also boost brain health by elevating levels of brain-derived neurotrophic factor (BDNF), a hormone that may protect against depression and various other mental conditions (42 , 43 , 44 ).
SUMMARY
Although rumors abound that it’s harmful, short-term fasting has powerful benefits for your body and brain.
11. Intermittent fasting makes you overeat
Some individuals claim that intermittent fasting causes you to overeat during the eating periods.
While it’s true that you may compensate for calories lost during a fast by automatically eating a little more afterward, this compensation isn’t complete.
One study showed that people who fasted for 24 hours only ended up eating about 500 extra calories the next day — far fewer than the 2,400 calories they’d missed during the fast (45 ).
Because it reduces overall food intake and insulin levels while boosting metabolism, norepinephrine levels, and human growth hormone (HGH) levels, intermittent fasting makes you lose fat — not gain it (27 , 46 , 47 , 48 ).
According to one review, fasting for 3–24 weeks caused average weight and belly fat losses of 3–8% and 4–7%, respectively (49).
As such, intermittent fasting may be one of the most powerful tools to lose weight.
SUMMARY
Intermittent fasting is an effective weight loss method. Despite claims to the contrary, no evidence suggests intermittent fasting promotes weight gain.
The bottom line
Numerous myths get perpetuated about intermittent fasting and meal frequency.
However, many of these rumors are not true.
For example, eating smaller, more frequent meals does not boost your metabolism or help you lose weight. What’s more, intermittent fasting is far from unhealthy — and may offer numerous benefits.
