Myths about intermittent fasting

Is fasting good for you read this before start?


“I fast for greater physical and mental efficiency”


People who newly encounter fasting often skeptical about its benefits, and concerned about adverse health effects. Human nature is more concerned about loss than gains. In this post I will try to answer common question is fasting good for you?

Why we need to fast?

Fasting is backed by thousands of years of traditions as well as new age scientific research. Fasting is an ancient practice, mentioned in ancient Greek, Egyptian and Hindu scripts. Fasting also mentioned in the Bible. Some of the oldest religions like Christina’s, Muslims, Buddhism, and Hinduism have some kind of fasting in practice.

We now live in a world where food is easily available. Often produced and processed by big corporations driven by monetary motives. Advertisements constantly tell us about how tasty and healthy processed food is. Corporations often make tall claims about products health impact, but there is no one to verify those claims. I am confused, is it a food or something else.

We now have 3 meals a day with snacks here and there. Our diet high on sugary delights, animal products but very low in vegetables. In result, people affected by Obesity and chronic diseases like diabetes/heart problems/stroke are skyrocketing.

It’s normal to have doubts about something you have always advised to avoid. Fasting is the easiest way to stop adverse effects on health caused by the modern diet.


1: Fasting makes you weak

Body regularly gets energy from glycogen, which is normally produced from glucose. Our diet is full of carbs and sugar. So our body never taps in stored fat for energy. When you fast body uses all the glycogen available in the body for energy.

Glycogen in body lasts for 24 hours without eating. When glycogen stores depleted body automatically starts converting stored fat to ketones which are used to fuel energy-hungry organs like brain, brain uses almost 20% of all energy produced. A process of converting stored fat to ketones is called ketosis.

If you have never done fasting before, it’s hard for the body to switch from glucose to fat for fuel. So in initial days of fasting, you experience weakness, but once you have a habit of fasting it’s gone. On a normal day, body keeps using fat for energy once fasting becomes habitual.

There are studies which shows that fasting preserve muscle mass, compared to traditional calorie restricted diet where you lose muscle mass and feel weak. [Study 1,2,3]


If you are new to fasting you may experience weakness or dizziness, but after some experience with fasting, you will feel as energetic before.


2: Fasting Slows down metabolism

Metabolic rate is defined as the amount of energy consumed by the body for a unit of time. BMR (Basal metabolic rate) is energy consumed during the resting time which is 70% of the energy used by body.

A common belief is that skipping meals causes body to slow down energy expenditure.  It is scientifically proven that long periods without food causes a slowdown in metabolism. Long-term fasting means fast which last more than 48 hours. [Study 4]

However Intermittent fasting (fast shorter than 48 hours) increase metabolic rate. There is a study which showed that intermittent fasting increased metabolic rate by 14%. [Study 5]

Fundamentally intermittent fasting is different from calorie restricted diet which forces the body to burn less and less energy over a period. In calorie-restricted diet, Body enters in starvation mode and start to burn muscles for energy, when muscles are burned body requires less energy to function hence metabolic rate decreases sharply.

In Intermittent fasting, no eating allowed for the period. Followed by normal eating, hence keeps body out of starvation mode and keep metabolic rate normal. [Study 6]


Intermittent fasting increases metabolic rate, whereas long-term fasting decreases metabolic rate.


3: Overeating after fasting

Authorities warn us that not having the meal, causes overeating in the next meal due to increased hunger. When we are hungry, food tests extremely good, because we are in an emotional state.

There are studies shown that people often overeat on breaking fast, but they can’t eat above a certain limit. Hence overall calories consumed after the fasting period is still less than total calories consumed on a normal day. Hence caloric deficit occurs which result in weight loss.

For example in 24 hours fast you consume 1 meal, whereas on a normal day in 24 hours one can have 3 meals with snacks.


Overeating happens but overall calories consumed is still far less than normal eating routine. When you get used to fasting your appetite stays normal and you avoid overeating.

Overeating is also a physiological issue, we need to deal it with mental alertness.


4:  Muscle loss

People often complain that they will lose muscles if they fast. To understand what really happens to muscles during fast is important.

Body gets energy from glucose and fats.

Body holds 500-600 gm of glycogen enough to provide energy for the first 24 to 36 hours which varies persons to person. Also, everyone has some amount of stored body fat ranging from 4% to 40% of body weight. Fats are extremely calorie dense, 1 gm of fat has 9 calories.

When body exhausted all of its glycogen, it starts converting body fat into ketones for energy, a normal person has pounds of fat stored, which can provide energy for another 10-20 days varies person to person. Called as fat oxidation. When body exhausted with stored fat, it starts converting muscles proteins into energy also called as muscle or protein oxidation.

Muscle gain or loss depends on exercise and diet. It has very less to do with fasting. Our bodies are evolved for a period of fasting and feasting. When we don’t have food to eat body usage stored fat for energy. In fact studies shown that fasting preserves muscle mass compared to calorie restricted diet. [Study  1,2]


Intermittent fasting or short-term fasting do not cause muscle loss. In long-term fasting when you fast more than 10-20 days muscle loss may occur when body fat percentage goes below 4%.


5: Fasting causes low blood sugar

People worried that their blood sugar will fall so low that they feel shaky and dizzy in fasting. Normally this will not happen, Human body has its own process to keep sugar levels to normal. Our bodies have enough stored energy for the next 20-30 days. [Study 7,8]

When people are new to fasting they experience these fake symptoms like shakiness or dizziness to overcome this take some salt with water. You will instantly feel better.

When you fast longer than 24 hours body goes in “ketosis”, and starts getting energy from ketones.  Ketones called as super fuel for brain. People experience extreme clear headedness and increase in concentration. Whereas fluctuating blood sugar levels causes mood swings and brain fog.


Unless you are type 1 diabetic or taking any medication to lower blood sugar, your sugar will stay normal in fasting mode.

In fact, if sugar is above the normal level it will go down to normal levels which is a good thing.


6: Malnutrition

Human body needs micronutrients like vitamins, minerals with macronutrients carbs, proteins, and fats.

For short-term fasting less than 24 hours you need not worry about vitamins and mineral, just concentrate on having micronutrient dense diet before and after fast. For longer duration fast have some multivitamin and multi-mineral supplement to counter deficiency.

Macro-nutrients like essential amino acids and fatty acids not produced in body. We need eat diet rich in these nutrients. During fasting stage body holds on to these essential macro-nutrients to stop wastage. The result is less stool formation. However after long-term fast one must have high fat and high protein diet rather than high carb diet to full fill body needs.


Short-term fasting you need not worry about malnutrition, for long-term fasting have a multivitamin and concentrate on taking high-fat high protein food before and after fast. People who need a lot of nutrients, like a pregnant woman should avoid fasting.


7: Reduce concentration or foggy brain

Our body has some ability to fake symptom’s to get what it wants. When we deprive the body of sugars and carbs we often feel foggy brain or reduced capability to do cognitive tasks.

Normally it should not happen, again newbie may feel poor concentration which goes after some experience with fasting. When you experience such symptoms just hold on, don’t eat or drink sugary drinks. Immerse yourself in deep work.

When you are in long-term fasting more than 24 hours, body enters the ketogenic state, and start producing ketones for energy. In ketones, brain experience a lot of clarity and concentration. [Study 9,10,11,12, 13]


Don’t fall prey to bodies false alarms, hold on for some time and see what happens. Keep yourself busy.


8: Social impact

Life is to live when you have to attend social events or gathering enjoy them fullest. Eat what you like. Enjoy what life offers.

For meeting choose a place where eating or drinking avoided or bluntly say no to eating.

For fasting, one should plan in advance and avoid periods of festivals and social gathering. Avoid stressful days both mental and physical.


Plan according to future events, enjoy life’s gifts.


9: What about breakfast

Breakfast promoted by companies looking for profit, by putting more food in your tummy. Breakfast is not necessary. There are studies showing no relationship between skipping breakfast and weight gain. [Study 14,15]

However, some people may perform better after having breakfast depends on person to person.

It’s simple, if you are hungry morning, have breakfast, skip breakfast if you are not hungry.


Breakfast is not important, it’s all up to you. Some people will perform better after breakfast and some don’t.


10: Fasting causes Starvation

Fasting is not starvation, you can have food whenever you want. Starvation is related to not having food to eat for prolonged periods.

Our bodies evolved for feasting and fasting, food abundance followed by food scarcity. Having 3 meals and snack in a day is luxury in the last century itself. Now also, most of the undeveloped world eat 1 or 2 time’s day, forget about snacks and sugary drinks.

Three meals a day made possible by modern day agriculture. Ancient times are rampant with food scarcity, people use to eat when they have food. Imagine hunter-gatherer diet are they eating 3 times a day? No, not at all. [Study 16 ]


Short term and long term fasting dot starve your body. It put stress on your body but starvation is more extreme than fasting.

If you are doing fasts smaller than 24-48 hours don’t worry about starvation.


11: It’s Unhealthy

No matter what you tell some people never satisfied, they will call fasting as unhealthy without doing it.

Remember what scientific research says about fasting.

Fasting is more beneficial than calorie restricted diet and very easy to follow. Saves you time and money, make your life better.

For list of benefits read this post.


Millions of people doing fasting from ancient times and reporting many benefits, I don’t see any harm why not to give fasting a try.


12: I am not overweight

Fasting is not only for losing weight, but fasting also have other benefits including lowering blood pressure to cancer cure. If you are not chronically malnourished or fighting with some deadly disease. Fasting going to improve your overall health by reducing the risk of common chronic diseases.

For list of benefits read this post.


Fasting is not only for obese people, a person having normal weight can also benefit from fasting.


13: It’s too difficult

Everything is difficult until you try it, we can always imagine how difficult is to do first ten pushups or riding a bike on a mountain road. We need to try it for a while and progress slowly to achieve our target.

If you think 24 hours fast is difficult, start with 12 hours fast, once you comfortable with 12 hours fast start with 16 hours fast and then 24 hours fast. Our body is the super machine it adjusts with changing the environment.

It will take some time see benefits of fasting, hold on for a while. Your commitment and dedication to fasting will automatically improve once you see the results.


Fasting is not at all difficult. Progresses slowly by skipping one meal in day or week and progress to 24 hours fast. Start small and committed for the period, make fasting a habit and progress upwards.


14: What about calorie restriction

Calorie restriction is part same old advice “Eat less move more”, It works to some extent but the damage it causes to body outweighs the benefits. When you consume few calories for a certain period, body adjusts with it by slowing metabolic rate.

If you on an average burning 2000 calories per day, body starts to burn 1800 calories per day. Which means body going in starvation mode. At some level weight loss plateaus. To kick start weight loss again you need to decrease consumption of more calories, means you need to eat 1400 calories now to lose the same amount of weight. [Study 17,18]

Even if you decrease calories severely body adjust it with by slowing metabolism. Body rarely taps into fat reserves.

In calorie restricted diet body start to lose muscle mass to save calories for important body functions. Your heart pumps blood slowly to conserve energy you feel lethargic and dizzy.

When caloric restriction done for longer period body functions severely impacted with muscle wastage.

Whereas in “intermittent fasting” no eating happens for the predetermined period, hence body uses all glycogen and then use fat to satisfy energy needs. Which very similar to how we lived from ancient times. When food is available, eat lavishly and when no food left, wait for next hunt.


Fasting avoids all the adverse impacts of caloric restrictions, and give us lots of other benefits.


15: I am not able to do my workout

Most of the negative effects about low energy caused by your mind. If you are not pro-athlete you hardly feel any difference. When glycogen level goes down body gets energy from fat which is sufficient for next 10-20 days.

Pro-athletes may have impact on performance because of low glycogen levels, which is very helpful for peak physical performance in short time, compared to ketones from fat.


Go and do your workout on time, don’t worry.

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