Word study on fasting

Life in the fasting lane can be brutal, especially if you go into fasting and prayer halfheartedly. The hunger pangs rumble our stomachs and suddenly carbs are a temptingly luscious lifeline. Many of us have a mindset that we’re restricting ourselves and therefore it’s punishment.

It’s not, prayer and fasting is where physical detox meets spiritual transformation. Fasting and prayer is where you nourish your spirit, and your fears starve death. Fasting helps detach us from this world while prayer re-attaches us to God. Yet, most of us haven’t participated in this sacred discipline or we’ve heard of it as intermittent fasting for weight loss.

Fasting is the spiritual discipline of denying ourselves something (typically food) to feast on the things of God. Fasting and praying are Bible-based disciplines that are appropriate for all believers of all ages throughout all centuries in all parts of the world. The word «fast» or «a fasting» is tsom in the Hebrew and nesteia in the Greek language. The literal Hebrew translation would be «not to eat.» The literal Greek means «no food.» 

 It’s a choice of abstinence from food. Fasting is a way to demonstrate to God, and to ourselves, that we are serious about our relationship with Him. 

What Does the Bible Say about Prayer and Fasting?

Jesus practiced fasting when he was tempted by Satan, (Matt. 4:1-11; Mark 1:12-13; Luke 4:1-4). During those 40 days of loneliness, “He ate nothing” (Luke 4:2). In fact, the earlier mention of fasting in the Old Testament were the instructions God gave Moses after leading his people to freedom in Exodus 13:3, “Then Moses said to the people, “Remember this day in which you went out of Egypt, out of the land where you were made to stay and work. For the Lord brought you out of this place by a powerful hand. No bread made with yeast will be eaten.” The book of Acts also records believers fasting before they made important decisions (Acts 13:2; 14:23). It allows us to take our eyes off the things of this world, we can more successfully turn our attention to Christ.

One of the many reasons why God called his people to fast had to do with the culture and times. Today, we can have a full meal in three minutes thanks to freezer foods and microwaves. Back then, hours upon hours went into food preparation. Fasting was a way to take the focus off ourselves and put it back on God. Jesus also gave us clear instructions on how to fast because it was meant to be a spiritual breakthrough, not pride.

«When you give up eating, don’t put on a sad face like the hypocrites. They make their faces look sad to show people they are giving up eating. I tell you the truth, those hypocrites already have their full reward. So when you give up eating, comb your hair and wash your face. Then people will not know that you are giving up eating, but your Father, whom you cannot see, will see you. Your Father sees what is done in secret, and he will reward you» Matthew 6:16-18.

What Does Prayer Do for Fasting?

Fasting and prayer are often linked together (Luke 2:37; 5:33). Fasting without praying isn’t fasting. It is dieting or deprivation. The only reason to fast is to make space for you to seek the Lord with greater urgency. Instead, we pray when we were supposed to be eating. Use the hunger pangs to remind you to remind yourself you hunger for God. In other words, fasting gives us more time for prayer and prayer helps tear down walls, utter us into spiritual breakthroughs, destroys chains, and gives us clarity of God’s answers that we seek!

When Jesus returns, fasting will be done. It is a temporary discipline for this life and age to connect our hearts to Christ and prepare us for when we will encounter Him face to face. When he does return, he will throw a glorious feast and there is a place at the table for each of us (Luke 14:16-17). Until then, we fast. 

How Do You Fast and Pray Biblically?

While Biblical fasting refers to food. There are a number of ways to fast. Remember, the point is to connect with God on a deeper level. A Fast is about humbling our hearts before God. Fasting and praying are about giving up the thing you seek for satisfaction in order to draw near to God… allowing God to satisfy you. The length of time and what you’re fasting from depends on what you sense God pressing you to do. How long you fast is entirely up to you and the leadership of the Holy Spirit.

You’ll want to put yourself on a schedule. Set aside ample time to be alone with the Lord. Listen for His leading. The more time you spend with Him, the more meaningful your fast will be.

Morning: 

Begin your day with praise and worship. Read and meditate on God’s Word. Invite the Holy Spirit to work in you and ask to be mindful of his presence. Pray for God’s vision and empowerment to do his will.

Noon: 

Return to prayer and God’s Word. If possible, take a short prayer walk. Journal what you sense God speaking to you.

Evening:

Get alone with God and seek Him. Spend time in intercessory prayer for your community and our nation’s leaders, for the world’s unreached millions, for your family or other needs.

What Is the Daniel Fast?

Daniel abstained from meat, bread, wine, and oils for his skin for 21 days (Daniel 10:3; Daniel 9:3).

These would have been things that satisfied Daniel, good food, and relief from dried skin. He abstained after being captured and brought to Babylon. It was likely the royal food was not kosher according to Daniel’s customs. When Daniel, Hananiah, Mishael, Azariah, and other young Israelite men were taken into Nebuchadnezzar’s service, they were to be given food and wine from the king’s table while undergoing a three-year training program. “But Daniel resolved not to defile himself with the royal food and wine, and he asked the chief official for permission not to defile himself this way” (Daniel 1:8). 

What Is a Partial Fast?

A partial fast is also known as a three-day spiritual fast. We see examples of Daniel and his friends eating veggies, fruit, and drinking water for ten days. They used this fast to honor God while in captivity. Others fasted using different lengths of time and how. This fast could last from part of a day to an entire day to several days or weeks (Esther 4:16; Joel 2:12; Ezra 8:21-23; Jonah 3:5-9).

What Is a Liquid Fast?

In this type of fast, there is no intake of solid foods. All food is replaced with liquids. Liquids can be consumed at any time. Make sure that you drink plenty of water, and you may also include fruit juices, vegetable juices, herbal teas, smoothies, smooth soups, and broth.

What Is a 40-Day Fast?

A complete fast is no food or water for a certain length of time. Jesus and Moses took it to the extreme. Both fasted for 40 days. (Exodus 34:28; Matthew 4:2).

What Is a Fast from Sex?

Before men went to war in biblical times, they sometimes abstained from sex wither their wives to fast. The New Testament also reveals to us that abstaining from sex (to fast) is a good thing to do when a couple decides on it together (1 Corinthians 7:5). This type of fast from pleasurable things short-circuits our tendency to lose appreciation for them. No matter how good something makes us feel, over time we take it for granted and lose the thrill.

What Is a Fast from Social Media, TV, Spending Money?

Sometimes the world gets a grip on us. Picking up our phones instead of our Bibles. Turning to wine instead of Christ to help us unwind. Zoning out on Netflix for hours on end instead of going to God with what we’re trying to numb ourselves from. I truly believe this is the enemy’s best and greatest tactic—to get us to turn to anything or anyone except Christ. Fasting from these things on a regular basis brings the presence of God back into focus. One can fast from any of these for any period of time.

Things to Avoid while Fasting and Praying 

Fasting is not about weight loss or causing health complications or marriage issues. Anytime a fast is being seriously considered, look at the calendar to ensure you won’t be doing anything to jeopardize your fast. It’s not a good idea to fast while taking the family to Disney World. It’s not a good idea of fast from sex unless you have the support of your partner. While you fast:

—        Avoid drugs, even natural herbal drugs, and homeopathic remedies.

—       Medication should be withdrawn only with your doctor’s supervision.

—       Limit your activity. Exercise moderately.

If you sincerely humble yourself before the Lord, repent and seek God’s face, you will experience breakthrough and his presence. Fasting and prayer are difficult, and it takes time to build spiritual muscles. Consider starting small. If you fail to make it through your first fast, do not be discouraged. You may have tried to fast too long the first time out. Fasting changes us for the better.

Photo credit: ©GettyImages/Pheelings Media

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Heather Riggleman is a believer, wife, mom, author, social media consultant, and full-time writer. She lives in Minden, Nebraska with her kids, high school sweetheart, and three cats who are her entourage around the homestead. She is a former award-winning journalist with over 2,000 articles published. She is full of grace and grit, raw honesty, and truly believes tacos can solve just about any situation. You can find her on GodUpdates, iBelieve, Crosswalk, Hello Darling, Focus On The Family, and in Brio Magazine. Connect with her at www.HeatherRiggleman.com or on Facebook.  

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This article is part of our larger resource library of Christian practices and disciplines important to the Christian faith. From speaking in tongues to tithing & baptism, we want to provide easy to read and understand articles that answer your questions about Christian living.

10 Things to Know about Speaking in Tongues
The Fruit of the Spirit — What Are They?
What Is the Tithe?
What Is the Sabbath and Is it Still Important?
Baptism — What Does it Mean and Why Is it Important?

Communion — 10 Important Things to Remember
Armor of God — What Is it and How to Use It
What Does it Mean to Be Righteous?
What Is Christening?
What Is Submission?

| Author: Dele Oke

Fasting

Fasting is consciously abstaining from food and drink: either entirely, or partially for a predetermined period of time. Fasting can also involve the abstaining from customary or choice nourishment and activities.

The purpose of fasting

Matthew 7:7-8 «Ask and it will be given to you; seek and you will find; knock and the door will be opened to you. 8 For everyone who asks receives; he who seeks finds; and to him who knocks, the door will be opened. (NIV)

To seek means to crave, and strongly desire something from someone. This is what God desires for us to do with Him. God wants people who will seek after Him (Luke 12:31). Fasting helps us to seek God.

Our body (or flesh) is our greatest hindrance to seeking God. Our flesh is very demanding. It craves for food and attention all the time. This can hinder us from focusing on God.

Fasting helps us to bring our bodies under control and focus on God. If you desire to hear God speak to you, or you have a particular prayer request that you strongly desire God to answer then fasting is a good way to approach it.

Ezra is a good example of a person who sought God’s face with prayer and fasting. He called a fast when he needed to get something from God.

Ezra 8:21-23 There, by the Ahava Canal, I proclaimed a fast, so that we might humble ourselves before our God and ask him for a safe journey for us and our children, with all our possessions. 22 I was ashamed to ask the king for soldiers and horsemen to protect us from enemies on the road, because we had told the king, «The gracious hand of our God is on everyone who looks to him, but his great anger is against all who forsake him.» 23 So we fasted and petitioned our God about this, and he answered our prayer. (NIV)

When we get close to God the devil flees (James 4:7-8). Since fasting helps us to draw close to God it means we can break the oppression of satan, sin and sickness over our lives as we pray and fast.

Isaiah 58:6 [Is] this not the fast that I have chosen: To loose the bonds of wickedness, To undo the heavy burdens, To let the oppressed go free, And that you break every yoke? (NKJV).

Different Fasts

1.Daniel’s fast

Abstaining from customary and choice nourishment for a fixed period of time

Daniel 10:2-3 At that time I, Daniel, mourned for three weeks. 3 I ate no choice food; no meat or wine touched my lips; and I used no lotions at all until the three weeks were over. (NIV)

You could have what is commonly called a Daniel’s fast. This means deciding not to eat certain customary foods such as bread, meat e.t.c. The advantage of this type of fast is that it is not so difficult on the body. It is a good way to introduce yourself to fasting.

A Daniel’s fast can also be sustained for much longer than a total fast since you will still be eating certain foods.

Abstaining from certain customary foods will also help you to focus your attention on God.

2. Total fast

Abstaining entirely from food for a fixed period of time.

Abstaining entirely from food for a fixed period of time is an effective way of fasting. If you have never done this before then you should start gradually. You could start by missing your morning meal.

After doing this several times you could progress on to missing your food for the whole day. It is a healthy habit to drink water while you fast. Since this helps to keep your body working properly. Remember that the point of fasting is to keep our focus on God.

After a while you should be able to fast for two or three days in a row. You could either break the fast every evening or fast right through.

You have to be very determined when going on a total fast for the first time. Initially your stomach will protest vehemently. Ignore it. You will not die.

3. Living a fasted life.

Philippians 4:5-6 Let your gentleness be evident to all. The Lord is near. 6 Do not be anxious about anything, but in everything, by prayer and petition, with thanksgiving, present your requests to God. (NIV)

The Bible encourages us to pray and petition (or seek) God continuously. To do this we will need to live a fasted life. This means abstaining permanently from those things which hinder our walk with God (Hebrews 12:1). Hindrances are not necessary sin. They could be normal activities of life which tend to take our focus away from God. We all need to look at our lives and ask the Holy Spirit to show us those things which hinder our walk with Him. We should then fast these things.

Is fasting necessary?

Matthew 6:16-17 «When you fast, do not look sombre as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full. 17 But when you fast, put oil on your head and wash your face, (NIV)

Notice that Jesus said «when you fast..» and not «if you fast». Fasting is necessary if we are to get closer to God. If we are to hold on to the power of God and do His work; casting out demons e.t.c we will need to put time aside to pray and fast.

Mark 9:27-29 But Jesus took him by the hand and lifted him up, and he arose. 28 And when He had come into the house, His disciples asked Him privately, «Why could we not cast it out?» 29 So He said to them, «This kind can come out by nothing but prayer and fasting.» (NKJV)

It is only by seeking God’s face that we will receive the anointing and power to do His work. In the Acts of the Apostles we see the Apostles pray and fast as they went about God’s work

Acts 14:23 So when they had appointed elders in every church, and prayed with fasting, they commended them to the Lord in whom they had believed. (NKJV)

Acts 13:2-3 As they ministered to the Lord and fasted, the Holy Spirit said, «Now separate to Me Barnabas and Saul for the work to which I have called them.» 3 Then, having fasted and prayed, and laid hands on them, they sent [them] away. (NKJV)

It is during times of fasting and seeking God that the Holy Spirit can speak to us and guide us. Not that He cannot speak to us at other times, rather it is because fasting helps us to be more sensitive to the voice of the Holy Spirit.

Practical tips on fasting

1. 1. Set aside a specific time for fasting and stick to it; no matter what your stomach says.

It is advisable to drink water during times of long fasting.

2. Fasting pray and study of the word go together. Try and make time to pray and study the word during times of fasting.

3. If you have never fasted before then a Daniel’s fast is a good one to start with.

4. Fasting helps us to seek God. It makes us more sensitive to the Holy Spirit. Times of fasting aid us in drawing closer to God since we focus on Him more during these times.

5. After fasting for a whole day it is advisable to end the fast with light food. Eating something heavy could upset your stomach.

6. Set regular time aside for fasting. There will be times when the Holy Spirit leads us to prompts us to fast. We should be sensitive to this prompting and obey.

Finding yourself confused by the seemingly endless promotion of weight-loss strategies and diet plans? In this series, we take a look at some popular diets—and review the research behind them.

What Is It?

Intermittent fasting is a diet regimen that cycles between brief periods of fasting, with either no food or significant calorie reduction, and periods of unrestricted eating. It is promoted to change body composition through loss of fat mass and weight, and to improve markers of health that are associated with disease such as blood pressure and cholesterol levels. Its roots derive from traditional fasting, a universal ritual used for health or spiritual benefit as described in early texts by Socrates, Plato, and religious groups. [1] Fasting typically entails a steady abstinence of food and beverages, ranging from 12 hours to one month. It may require complete abstinence, or allow a reduced amount of food and beverages.

Prolonged very low calorie diets can cause physiological changes that may cause the body to adapt to the calorie restriction and therefore prevent further weight loss. [2] Intermittent fasting attempts to address this problem by cycling between a low calorie level for a brief time followed by normal eating, which may prevent these adaptations. However, research does not consistently show that intermittent fasting is superior to continuous low calorie diets for weight loss efficiency.

How It Works

The most common methods are fasting on alternate days, for whole days with a specific frequency per week, or during a set time frame. [3]

• Alternate-day fasting—Alternating between days of no food restriction with days that consist of one meal that provides about 25% of daily calorie needs. Example: Mon-Wed-Fri consists of fasting, while alternate days have no food restrictions.
• Whole-day fasting—1-2 days per week of complete fasting or up to 25% of daily calorie needs, with no food restriction on the other days. Example: The 5:2 diet approach advocates no food restriction five days of the week, cycled with a 400-500 calorie diet the other two days of the week.
• Time-restricted feeding—Following a meal plan each day with a designated time frame for fasting. Example: Meals are eaten from 8am-3pm, with fasting during the remaining hours of the day.

The Research So Far

Physiologically, calorie restriction has been shown in animals to increase lifespan and improve tolerance to various metabolic stresses in the body. [4] Although the evidence for caloric restriction in animal studies is strong, there is less convincing evidence in human studies. Proponents of the diet believe that the stress of intermittent fasting causes an immune response that repairs cells and produces positive metabolic changes (reduction in triglycerides, LDL cholesterol, blood pressure, weight, fat mass, blood glucose). [3,5] An understandable concern of this diet is that followers will overeat on non-fasting days to compensate for calories lost during fasting. However, studies have not shown this to be true when compared with other weight loss methods. [5]

A systematic review of 40 studies found that intermittent fasting was effective for weight loss, with a typical loss of 7-11 pounds over 10 weeks. [2] There was much variability in the studies, ranging in size from 4 to 334 subjects, and followed from 2 to 104 weeks. It is important to note that different study designs and methods of intermittent fasting were used, and participant characteristics differed (lean vs. obese).  Half of the studies were controlled trials comparing the fasting group to a comparison group and/or a control group (either continuous calorie restriction or usual lifestyle), with the other half examining an intermittent fasting group alone. A brief summary of their findings:

• Dropout rates ranged from 0-65%. When comparing dropout rates between the fasting groups and continuous calorie restriction groups, no significant differences were found. Overall, the review did not find that intermittent fasting had a low dropout rate, and therefore was not necessarily easier to follow than other weight loss approaches.
• When examining the 12 clinical trials that compared the fasting group with the continuous calorie restriction group, there was no significant difference in weight loss amounts or body composition changes.
• Ten trials that investigated changes in appetite did not show an overall increase in appetite in the intermittent fasting groups despite significant weight loss and decreases in leptin hormone levels (a hormone that suppresses appetite).

A randomized controlled trial that followed 100 obese individuals for one year did not find intermittent fasting to be more effective than daily calorie restriction. [6] For the 6-month weight loss phase, subjects were either placed on an alternating day fast (alternating days of one meal of 25% of baseline calories versus 125% of baseline calories divided over three meals) or daily calorie restriction (75% of baseline calories divided over three meals) following the American Heart Association guidelines. After 6 months, calorie levels were increased by 25% in both groups with a goal of weight maintenance. Participant characteristics of the groups were similar; mostly women and generally healthy. The trial examined weight changes, compliance rates, and cardiovascular risk factors. Their findings when comparing the two groups:

• No significant differences in weight loss, weight regain, or body composition (e.g., fat mass, lean mass).
• No significant differences in blood pressure, heart rate, fasting glucose, and fasting insulin. At 12 months, although there were no differences in total cholesterol and triglycerides, the alternate-day fasting group showed significantly increased LDL cholesterol levels. The authors did not comment on a possible cause.
• The dropout rate was higher in the alternate-day fasting group (38%) than in the daily calorie restriction group (29%). Interestingly, those in the fasting group actually ate less food than prescribed on non-fasting days though they ate more food than prescribed on fasting days.

A one-year randomized trial also did not find intermittent fasting (16:8 method) more beneficial than calorie reduction without a restricted eating time. [7] Patients with obesity were placed on the same moderate calorie restriction but randomized to one of two groups: time-restricted eating (allowed to eat from 8am-4pm), or allowed to eat any time. Weight, waist circumference, body mass index, body fat, and blood work were measured. At one year, the time-restricted group lost an average of 18 pounds and the time-unrestricted group lost 14 pounds; blood pressure, cholesterol, and blood glucose levels also decreased. However, the changes in weight and other parameters were not significantly different among the groups.

Potential Pitfalls

This type of dietary pattern would be difficult for someone who eats every few hours (e.g., snacks between meals, grazes). It would also not be appropriate for those with conditions that require food at regular intervals due to metabolic changes caused by their medications, such as with diabetes. Prolonged periods of food deprivation or semi-starvation places one at risk for overeating when food is reintroduced, and may foster unhealthy behaviors such as an increased fixation on food. [8,9]

Individuals with the following conditions should abstain from intermittent fasting:

• Diabetes
• Eating disorders that involve unhealthy self-restriction (anorexia or bulimia nervosa)
• Use of medications that require food intake
• Active growth stage, such as in adolescents
• Pregnancy, breastfeeding

Unanswered Questions

• How often and for how long should one fast to see a therapeutic benefit?
• Is this diet safe and beneficial for everyone (e.g., generally healthy population, higher risk individuals with chronic diseases, elderly)?
• What are the long-term effects of intermittent fasting?
• Is there a risk of negatively influencing the dietary behaviors of other family members, especially in children who see their parents abstaining from food and skipping meals?

Bottom Line

Although certain benefits of caloric restriction have been demonstrated in animal studies, similar benefits of intermittent fasting in humans have not been observed. It is unclear that intermittent fasting is superior to other weight loss methods in regards to amount of weight loss, biological changes, compliance rates, and decreased appetite. Certain people who typically eat one or two meals a day or do not eat for long stretches of time may show better compliance with this type of regimen. Additionally, people who tend to eat or snack excessively at night may benefit from a cut-off eating time, especially if the late eating leads to unpleasant side effects such as reflux or disrupted sleep.

More high-quality studies including randomized controlled trials with follow-up of greater than one year are needed to show a direct effect and the possible benefits of intermittent fasting. Strong recommendations on intermittent fasting for weight loss cannot be made at this time.

Related

• Healthy Weight
• The Best Diet: Quality Counts
• Healthy Dietary Styles
• Other Diet Reviews

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Background

I got a ton of questions from patients and readers about the recent UCSF study on a form of fasting called time-restricted feeding (TRF), being ineffective for weight loss.  This is a perfect opportunity for me to dig deeper into how fasting can either be a powerful tool that potentially promotes weight loss and enhances overall health, or potentially does the very opposite.

I also recommend you listen to my podcast titled “Have We Taken Fasting Too Far?” which you can listen to on my site here or on your favorite podcast player (Meta Health Podcast episode #7).

The Study

This was a randomized control study (the highest quality study design) looking at 116 overweight or obese adults that were split into the following 2 groups:

1. CMT (Consistent Meal Timing) Group: This group was told to eat 3 structured meals per day, but they could eat ad libitum, meaning anything they want at whatever quantity they want.  Participants were also allowed to snack between meals.
2. TRE (Time-restricted Eating) Group: This group was also allowed to eat ad libitum, but only between the hours of 12p to 8p.  This is the popular 16/8 fast where you eat for 8 hours and fast for 16 hours.

The study lasted 12 weeks and the primary outcome was weight loss and secondary outcomes were fat mass, lean mass, fasting insulin, fasting glucose, and A1C levels and a few others.  Some of the findings were as follows:

1. Weight Loss: Both groups lost a little weight, but there was NO difference between the 2 groups.  In other words, TRE was no better than eating 3 meals a day.
2. Body Composition: No significant change in whole body fat mass between both groups, but there was a significant decrease in lean body mass (muscle) in the TRE group but not the CMT group.  In other words, the fasters lost significantly more muscle.
3. Cardiac Risk Markers: There were no significant overall differences in lipids, glucose, fasting insulin and other cardiometabolic markers.  Interestingly there was a significant drop in the systolic (top blood pressure number) blood pressure for the CMT group but not the TRE, while the opposite was noted for the diastolic (bottom blood pressure number) where the TRE group had a significant drop but not the CMT group.
4. Oura Ring Data: The Oura ring measures sleep, activity, and other metrics like heart rate variability and temperature.  There was a significant reduction in daily movement in the TRE group but not the CMT group.

So in summary, when compared to CMT, TRE showed no improved weight loss, caused more muscle loss, had no appreciable impact on heart disease and metabolic risk markers and the Oura ring data showed a reduction in daily movement which might imply a lower energy state.  Is this a nail in the coffin for intermittent fasters?

News Headlines

I applaud the UCSF team for performing the highest quality study design to investigate whether TRE is effective.  However, as a reminder from my previous writings, recall how nutrition studies, even when done under “rigorous conditions,” are the bottom of the barrel when it comes to research.  Unfortunately these studies deteriorate from study to news headlines to lay reader interpretations.  I discussed this destructive process in detail in this post where I dissect the anatomy of nutrition headlines while analyzing a study on low carbohydrate diets.

The degenerative process from study to lay interpretations further led to e-mails and questions to me asking “I heard fasting doesn’t work” or “Did you read that fasting makes you lose muscle?”  and so on.  In other words, the practice of fasting, which has been around for thousands of years has been not only questioned but deemed ineffective (by many lay readers and even researchers) through a single 3 month study involving just over 100 participants.  Read the headline below published in UCSF’s own newsletter

The main title says TRE doesn’t work and the subtitle connects TRE to intermittent fasting (IF), so the conclusion from just skimming this UCSF-published newsletter is that TRE and IF are ineffective for weight loss.  I was especially surprised by the bold and definitive nature of this headline (“Doesn’t Work”) given the intrinsically flawed and uncertain nature of nutrition studies, including this one.

Now let’s back off these headline generalizations and get specific.  This study did not cover all forms of fasting, deeming fasting an altogether ineffective practice.  It looked at a very specific form of fasting called time-restricted eating (TRE).  The study was also insufficient in saying TRE doesn’t work, because it further used a very specific eating window from 12p-8p.

This study looked at TRE as a singular intervention in the absence of other lifestyle practices (prescribed exercise, specific nutrition guidelines during eating window, sleep and stress management, etc.). Is this sufficient to put a nail in the coffin for fasting?  Let’s discuss further.

Muscle Loss Is An Issue

When I look at research headlines on interventions that I use in my clinical practice, I try to connect study findings with my anecdotal clinical findings, in addition to looking at a larger body of research and time-tested ancestral traditions (if available), to make more definitive assumptions, but not conclusions.

Researchers and clinicians need to keep an open mind as they explore lifestyle interventions like fasting, and for physicians like myself and others who have used it successfully in practice for years, reading definitive headlines and conclusions from researchers who have little to no clinical experience in using fasting therapeutically leaves me a little frustrated.

The findings from this study that do resonate for me are the loss of muscle.  This is a real finding which I see over and over in my patients who fast improperly.

Fasting is a double-edged sword where one edge of the blade can cut body fat, but the other edge can also cut essential muscle if fasting is not prescribed in conjunction with other lifestyle changes like optimal protein intake and strength training.

This is why I’ve written extensively on the importance of protein intake here and the importance of muscle mass here.  For those of you who are my patients, you know how much I emphasize protein intake and strength training and have highlighted these in my book as well.

One of the greatest benefits of fasting done the right way is reduced hunger.  My patients lose their craving for excessive carbs, sweets, and processed foods.  That’s a really good thing that individuals eating 3 meals and 2 or more snacks (the CMT group in the study was allowed to snack) rarely experience.  The down side of reduced hunger, and this is occasionally an issue for me, is you have to literally remind yourself to eat sometimes and when you do eat, you might actually undereat.

I see this often in my patients who have adopted fasting.  Their caloric intake is often low and their protein intake is often abysmal.

Individuals who combine fasting with a sedentary lifestyle or an exercise program that neglects adequate strength training will inevitably lose muscle and eventually gain back body fat very quickly.

The UCSF study findings correlate with this same observation I’ve seen in the clinic for years, and they even cite another study that highlights this point when they mention “the extent of lean mass loss during weight loss has been positively correlated with weight regain.”  Again, refer to my protein and muscle posts mentioned earlier for context and guidance.

The most powerful trigger for muscle preservation and growth is sufficient strength training.

You can’t guzzle protein shakes and eat protein bars while sitting all day, expecting that dietary protein will spontaneously grow muscle without you doing any meaningful physical work.

This will likely contribute to caloric overload and weight gain, or go to the liver to be converted to glucose.  Strength training must be combined with adequate protein intake.

Finally, most of my patients can’t easily tell that they are losing muscle.  Muscle deterioration (aka sarcopenia) can happen in a subtle manner if you are not tracking it, and looking at yourself naked in a mirror won’t tell the story.

This deterioration progresses more rapidly as we age, and I have many patients who are 50 and older who don’t realize that the majority of their weight loss is coming from muscle loss, not fat loss.  Yes their belly might be flatter, but their muscles are also deflating which to me is an ominous sign.

Preservation of muscle is one of the most significant markers of longevity and overall quality of life, so it must be tracked.

If you are familiar with my work, you should know about how important muscle is as a glucose disposal organ.  After meals, around 80% of the glucose goes to your muscle parking lot to be stored or burned for energy.  Progressive muscle loss will reduce your ability to clear glucose from your blood stream, a major contributing factor to insulin resistant conditions (prediabetes, diabetes, heart disease, etc.).  This is a situation where fasting improperly can make insulin resistance and blood glucose control worse.

Doing specific, measurable weight training exercises also serve as a key barometer of your muscle strength.  Are you making slow but steady progress on your lifts and/or body weight exercises over time?  I know my pull-up max, my push-up max, my squat max without weights.  I also know my max for weighted deadlifts, lunges, squats, bench press, etc.

I’ve been using resistance bands recently and know how many reps I can do with different exercises using different bands.  I know my 1 mile run time, my 5K time, my 400m sprint time, and my vertical leap.  You get the picture and no, you don’t need this many metrics, but do choose a few.

Objective measurements of strength and endurance are at least as important and I would argue more important than regular measurements of lipids, glucose, and other common biometrics.

These are your performance vital signs.  For endurance measurements, please read my VO2 max post here if you haven’t.  Measuring limb circumferences and chest span may be a rough tool for measuring muscle mass, but it doesn’t always reflect strength.  For example, my legs are getting progressively stronger from exercise, but they are not necessarily getting much visibly larger.  Functional strength is far more important than visible size increases.  Arms and legs can grow larger from fat and bloating from excess glycogen and water, which doesn’t translate into significant strength improvements.

When it comes to body composition, there are 3 categories of body composition to keep in mind and I’m going to expand on the 2nd one because it is the one that is most easily missed, with potentially devastating consequences on long term health and quality of life.

1. A gain in body/belly fat with a loss of muscle strength: This is the absolute worst outcome.  Increase in inflammatory belly fat with a reduction in metabolically active, longevity-promoting muscle.  Avoid this at all costs through proper nutrition and exercise.

2 A loss in body/belly fat with a loss of muscle strength:  This is a common scenario in my fasters or patients that are undereating.  I see this so often in my seniors and/or vegetarians who are undereating calories, especially protein.

The problem is they think they are healthier because their waistline is slimmer, but their loss in muscle strength, especially in their legs, contributes to future disability, dementia, impaired immunity, and chronic disease.

I recently saw a 68 y/o Indian male in the clinic who I’ve known for years.  He was proud to report a weight loss of 15+ pounds during the quarantine due to intermittent fasting and deliberately cutting back his overall animal protein intake.  I congratulated him on his visibly smaller belly, but I noticed since he always wears shorts and a t-shirt, that his limbs had become much slimmer.  He had loose skin on his arms and legs and no appreciable muscle mass.

This was highly concerning to me.  He stopped weight training since his gym shut down.  I prescribed a higher protein diet (mostly plants and some animal) and gave him a guide with free weights and resistance bands that he could start using at home.  He e-mailed a few weeks later telling me he was absolutely shocked at how much strength he had lost from stopping weight training and just walking exclusively for exercise.

I love walking and recommend it to patients, but it is NOT strength training and it barely builds any muscle to counteract our mostly sedentary lives.

I estimate that the majority of this patient’s weight loss was from muscle.  Beware of this phenomenon in yourself and in any elderly family members, especially those who have taken on a more restrictive diet (fasting, vegetarian/vegan, etc.).  If you need more vegetarian sources of protein, read my post here.  There are plenty of plant-based bodybuilders and athletes who are able to gain strength without meat.

Don’t use your vegetarian status to under consume protein. Just remember if you aren’t regularly assessing strength and training, you can rapidly lose muscle mass without noticing it.  Using a personal trainer is another way to help you train and track muscle if you need a guide and further motivation.  It is one of the best investments you can make in your health and the health of those you care about.

3. A loss in body/belly fat with a gain in muscle strength:  This is the ideal combination we all need to strive for.

So bottom line is If you are fasting and getting simultaneously weaker and more winded despite losing weight, that’s a key sign that you are losing significant amounts of muscle mass and mitochondrial density.  Not only are you at a high risk for regaining body fat, you are shortening lifespan instead of extending it.

Timing and Frequency

The other pitfall in this study was the time interval used.  I think 8p is a late ending to an eating interval, especially in overweight/obese low metabolic individuals who are told they can eat whatever they want in unlimited quantities.  Unlike metabolically health individuals who can clear glucose rapidly after meals, these individuals take up to several hours to clear glucose.  They are likely going to bed with elevated sugars.

I have played around with the eating end times in different patients and although the optimal end time varies, most benefit by finishing all their eating by 6 or 7p and others have done even better when  finishing earlier (4 or 5p).  The point is you need to follow your own metrics and experiment with different eating windows.  This study just used one and made a comprehensive and conclusive statement.

This would be analogous to me doing a similar study on patients with high blood pressure and giving the study group a microdose of a blood pressure pill and comparing them to a placebo group who took no medication.  By the end of the study I would likely find no difference in benefit due to such a small dose, but this would be due to an insufficient dose of the blood pressure pill.  Would my overall conclusion be blood pressure pills are therefore ineffective at lowering blood pressure, despite there being multiple classes and doses of different blood pressure pills?  You get the picture.

How often TRE is dosed during the week can be variable.  I have patients who thrive by doing TRE every single day.  Others just need it a few times a week.  I personally do a version of fasting called IF, but instead of standing for intermittent fasting, it’s Intuitive Fasting.  I can tell when I need to give my body a longer break from food with a fasted exercise session, while on other mornings I wake up and know I need to eat breakfast.  Again, self-experimentation is key here.  Apart from intuition, I might occasionally check quantitative measures to guide me (weight, glucose, ketone levels, etc.).

Fasting Must Be “Prescribed”

The big message from this post is that fasting is a drug that comes in different formulations and doses and must be personalized and prescribed just like a drug, if we are using it therapeutically to achieve a specific goal (weight loss, reduce cholesterol, etc.).  This is similar to exercise.  Exercise at the wrong dose and frequency can promote injury, excessive hunger, and other complications.  Done properly, exercise can burn body fat and have endless other health benefits.

If you want to enhance the effect of fasting, you must do the following:

• Self-experiment to find the right interval and dosing regimen
• Pay attention to what you are eating during the eating window.  Sufficient protein, plants and other nutrient dense foods are essential.  Schedule meals if you tend to under eat and stock up on protein sources or use a healthy meal delivery service to keep you on track.
• You must combine fasting with an exercise program that includes strength training
• Track yourself periodically by monitoring body metrics (weight, waistline, body fat possibly), metabolic numbers (lipids, glucose, etc.), and performance (strength and aerobic).  If you are getting weaker and/or endurance is taking a hit during exercise, you may need to refeed and put a pause on fasting while you refuel.
• Consider working with a dietitian or doctor who is experienced with prescribing and personalizing fasting.

One other key point I want to make is to pay attention to hunger after you become healthier.  When we chronically overeat and eat the wrong foods, our hunger signal is aberrant and driven by the addictive nature of foods and other miscues like chronic stress and sleep deprivation, rather than authentic biological hunger.

When you stop overeating and eat clean, then hunger becomes a natural signal you must pay attention to.

I worry about my overdriven patients who fast every single day for 18+ hours despite their intensive work and workout schedules.  It’s very difficult to squeeze in all the necessary protein and nutrients into a 6 hour window on a daily basis, and some days your body might need more, especially if you are exercising hard.  Don’t try to discipline your way out of hunger.  I’ve done that before and paid the price.

I hope this post helps you understand the finer nuances of fasting and also serves as another of my recurrent reminders of being highly skeptical of conclusive headline studies, especially involving the field of nutrition.

Resources

Be sure to listen to my podcast episode “Have We Taken Fasting Too Far?” which you can access on my site here or on your favorite podcast player (Meta Health podcast, episode #7).

When I first started intermittent fasting in 2017, I don’t remember finding nearly as much content on the subject on the Internet. Articles on big websites like Healthline or WebMD seemed to be advising against it pretty strongly.

Now even they, in some articles, came up with good things to say on the subject. And everybody and their mother seemed to have created it’s very own list of benefits about fasting.

So, I wanted to create the ultimate resource on the benefits of fasting, not only telling you you’ll lose weight and feel more energized but literally every benefit, even side ones, I’ve learned about by reading articles or studies and through my own 3+ year of experience in the practice.

During this time I converted friends to intermittent fasting and prolonged fasts and they also gave me their feedback, I spent some time talking about it and asking questions because it’s such a fascinating subject. And they came up with even more benefits!

I will start by talking about everyday life. Because you don’t want to start a list with yet again some guy telling you “fasting is good for burning fat”. I’ll get to that of course, but I wanted to start with what I’ve learned from experience.

The last chapter benefit, to me, is the single greatest benefit you’ll get from implementing any type of fasting.

A big disclaimer (before I begin)

I am not a doctor, I don’t own a Ph.D., I’m not specialized in fasting, I’m just a regular guy compiling information on a subject I love and that really helped me in my life.

I’ll be talking about the effects fasting could have on severe conditions, I’ll be backing these claims with studies, but don’t just take my word for it. Do your own researches and follow your doctor’s orders.

The idea of this article is merely to present to you how fasting can improve your life or condition, don’t suddenly stop your medication and start fasting instead. Educate yourself on the subject, compile information, it could help you talk to your doctor about it with a good understanding of the subject.

I really want to put emphasis on this: I want to help you open up to the benefits fasting can have, help spread the word. But I don’t want to make people think that’s the miracle cure for everything.

1. Increase your willpower

Did you know that your willpower was finite? That it is like a muscle that you can train? Willpower can actually be measured through heart-rate variability (HRV). In short, the variations in the interval between each heartbeat.

HRV is an important factor and the higher HRV, the easier it will be to deal with stress, ignore distraction, delay gratification, etc. To summarize, the higher HRV, the greater the willpower.

When you fast, you’re training your willpower muscle, since you’re forcing yourself not to eat when your hungry, not indulge in sugar drinks, etc. But implementing fasting in your life will also improve your diet, energy and sleep quality. All important factors to increase HRV.

In a study, several patients did a 4 months money management experience, where they had to log every expense they did, all the while under a pretty tight budget. Meaning they couldn’t go out much (restaurants, movies, etc.).

The willpower exerted during these four months actually spilled on other aspects of their life, they drank less coffee or alcohol, started exercising, etc.

Take it from me: since I started fasting in 2017, I exercise, take cold showers and meditate every day for example. Oh, and I also quit my job and started my company! I don’t think the only reason for this is fasting, but I’m pretty sure it helped.

Through fasting, you’ll get used to increase your willpower to the extent where you’ll need to put yourself in some kind of discomfort/discipline with other aspects of your life, you’ll love creating new healthy habits.

2. Less stomach bloating and going to the bathroom

I have struggled with bloating and digestive problems since my adolescence. I was pretty sure I was suffering from a slight case of irritable bowel syndrome. Fasting completely changed that.

Of course, it still happens sometimes when I eat too much, carb load on a meal, when on vacation and eating 3 times a day. But most of the time, meaning 90% of the time, I feel less bloated and my stomach feels fine.

When fasting, you’ll be getting tons of water and you’ll be giving your digestive system a break. And you’ll give him a break almost every day, by reducing your eating window. And also reducing the amount of food you eat.

If you keep hydrated, eat less and less often, you’ll definitely reduce bloating and bowel movements. Before intermittent fasting, I was going to the bathroom 3 to 4 times a day, now hardly one time. Less bloating, less gas, fewer bowel movements.

Let me also add a side note on this: I also greatly reduced carbs consumption in the last year, especially refined carbs, keeping them to a minimum during the week. I can really feel it improved my condition even more.

3. Better sleep

In order to explain how and why you’ll get better sleep, let’s first take a look at how fasting will mess with your sleep at first. The first reason being your internal body clock, the second the fact that you’ll be forcing your body to burn fat for energy.

We all have several internal body clocks (in the brain, liver, heart, etc.), which is called the circadian rhythm. What and when you eat will have a great impact on circadian rhythm.

In short, from the first bite of food you get in the morning until that last thing you eat in the evening, this will tell your body how to set the circadian rhythm.

So of course at first, you’ll be messing up with this rhythm, since you’ll be eating twice, or even once a day instead of 3 times or more. Your body is a machine of habit, altering this rhythm won’t be easy and it will fight it at first.

The second thing that’ll impact your energy and sleep quality is turning your body’s machinery into burning fat instead of glucose. When fasting, once glycogen stores, sugar in the body, are depleted after around a day, your body will have to use fat for energy.

But it’s not used to do that. That will lead to fatigue, headache, brain fog, also known as keto flu. Your body will fight against getting into ketosis and trigger those side effects.

After a while though, once you’re body’s used to the newly imposed circadian rhythm and to ketosis, all these effects will disappear and make way for actual benefits.

First, when doing any type of fasting, you’re restricting your eating window. This study has shown that patients reducing their eating window from 14h to 11h experienced better sleep quality. Because you’re actually creating a stronger circadian rhythm for your body.

Second, insulin levels have a direct impact on melatonin secretion. Melatonin is the sleep hormone. In short, your body prefers to eat and digest food during the day. The less you eat right before bed, the better the sleep quality.

Fasting will also increase insulin sensitivity, by reducing insulin levels in the body. This means you’ll get far less insulin floating around in the blood. The lesser insulin, the better the production of melatonin.

Lastly, I talked in my previous point about feeling bloated and how fasting will help with that. Going to bed feeling well, without any stomach ache or gas will be easier when fasting.

I did a whole article on how keto and fasting affected sleep and energy, if you want to know more about that, check it out.

4. Help quit/reduce smoking

This one benefit comes from a friend I often talk about here. She’s a smoker and she also experiences with fasting. She’s the catalyst for two articles I did: will smoking break a fast and this one where I wonder if fasting can help you quit smoking.

The short answer? It won’t cause you to quit smoking directly. But through other pathways, it could help reduce the habit.

First, as I said earlier, fasting will train and improve your willpower, there’s no question about it. You’ll impose discipline on yourself, embrace discomforts and this can lead to other drastic changes in your life.

I mentioned earlier a study on money management and the willpower spilling on other parts of their life. They drank less coffee and alcohol, exercised more, but also, smoke less.

Second, smoking is a bad habit. And it is exactly that: a habit. Like any habit, it needs a certain cue to be triggered. So, you’re a smoker, you just had something to eat (that’s your cue), you smoke a cigarette (that’s called the pattern) and you feel better (that’s the reward). We could see the same pattern with feeling stressed out or anxious.

Every habit works like that, good or bad. If you want to learn more about habit formation, I strongly advise you to read a great book called the Power Of Habits, which I talked about here. Not eating for a whole day, improving your mood and overall energy with fasting, all these side effects could help reduce smoking from a habit standpoint.

Third, my friend who’s intermittent fasting even did several days of fasting while smoking. Again, I told her it was a bad idea, but she did it anyway.

She was used to getting a smoke with her coffee, so at first, she had her cue to smoke quite often. But after the third day, cue or not, she started smoking less, like not even half of what she was used to smoking on a normal day.

I asked her if the didn’t like the taste as much, if it was making her dizzy or ill, etc. Which would be perfectly fine assumptions. But no, she just didn’t feel the urge to smoke as often.

Lastly, I almost always speak about fasting for weight loss, but when done for spiritual (or even simply detox) reasons, it can have surprising effects on bad habits. For example, the practice of Ramadan really helped people reduce or quit smoking altogether.

5. Feel free to eat what you want

To sell intermittent fasting to people I often talk about that. You’re not counting calories, you’re not replacing cream with milk, looking for light mayonnaise or other stupid food industry aberrations. You’re not eating as often, so you’re eating less, so you eat what the hell you want!

I know that seems counter-intuitive when speaking about diet to say eat what you want. Eating pizzas or hamburgers every day as your only meal is stupid. You shouldn’t be fasting a whole day and then getting junk food just, well, because.

I simply want to put emphasis on the fact that you will be less stressed about the way you eat. If you want to lose a lot of weight, of course, you should also change your diet, eat fewer carbs, more healthy food, reduce or cut sugar altogether, etc.

In the case where you’re just trying to lose a bit of weight and stabilize it though, when you eat and how much will be impacted greatly by intermittent fasting. And I believe it’s more important than WHAT you eat.

Anyway, as you’ll see in my next point, if you’re implementing fasting you’ll also get used to eating healthier meals and crave sugar and junk food less.

6. Less appetite

There are two hormones controlling hunger in the body: ghrelin and leptin. Ghrelin will regulate your appetite and leptin, which is a hormone found in fat cells, will tell you you’re satiated.

The first big worry everybody has with fasting is hunger. The meer thought of not eating for a day and being hungry terrifies people. If you don’t eat for several days, you should get increasingly more hungry, should you not?

It’s quite the opposite actually. This study conducted on six healthy volunteers, men and women, used to eat three times a day, had them fast for 33 hours. During the fast, ghrelin secretion in the blood was measured every 20 minutes.

In this graphic of the experiment you can see ghrelin levels being very low in the morning, meaning that’s when you should be less hungry, but that’s also when you’ve spent the longest time without eating. Levels rise again at lunch and at dinner.

You might think if they raise, then that’s your body telling you to eat. Yes, but no. Since ghrelin levels don’t continuously rise, they peak at the time you’re used to eating. Times when your circadian rhythm knows you usually eat, then fall back down.

A one day experiment doesn’t exactly tell us that fasting can cure hunger. Here’s a study that was done for 3.5 days on 33 patients, lean and obese. You can see in the graph below that over the fast, overall ghrelin levels decreased.

Again, the less they ate, the less ghrelin secretion, the less appetite. This is particularly apparent with women as you can see, where ghrelin levels in men do go down, but far less. I’ll talk about this in my next point.

Now from a personal standpoint, I can say that’s a hundred percent true. Without even realizing it, intermittent fasting really reduced my overall appetite and, as we’ll talk about in my next point, my cravings.

What’s funny is the whole “you’ll starve and then eat more to compensate” thing. Try not eating for a day and be amazed at how quickly you’ll feel satiated when you’ll break your fast with dinner.

7. Reduce cravings

Going back to the previous point on appetite, I mentioned that women seemed to have more ghrelin secretion than men. Reading about this, I’ve seen many saying that this could come from reduced cravings.

Meaning, the women patients in this experiment, and even any woman for that matter experience more cravings for sugar, or refined food. And according to this study, it might be on the point.

Not because women have less willpower than men when it comes to this, but, to quote the study:

Furthermore, for women, there are sex hormone-related variations in craving and food cue reactivity that may hinder dieting and weight loss attempts.

The study also concludes that further researches should be done on craving variations during menstruations.

But wait, why am I talking about that? Because if women, overall, suffer from cravings more than men, then this graph could help emphasize that fasting helps reduce those cravings. With ghrelin levels being almost similar at the end between men and women:

A bit of a stretch? It might be, so let’s look at this other study, which took a look at brain stimuli people got when seeing food slides. They studied the level of stimuli both in fasting obese patients and dieting ones.

At the end of the three weeks experiment, reaction to craving didn’t seem to change in people dieting, but the stimuli got close to zero for the fasting group.

On a personal note, did the implementation of fasting in my life since 2017 reduced cravings? Yes, but not necessarily sugar cravings. I’ve never been a big sugar guy, so what I felt hit the most was carbs cravings. Pasta, pizza, bread, I love these, but I can simply do without most of the time.

Before I was eating pasta three times a week, it was my go-to meal. And don’t even get me started on bread!

Now that I’m fasting and I cut down the carbs, I enjoy eating these more when I get to, but most of the time I don’t crave them. And usually, after indulging, I’m good for a few days.

8. Prevent jet flag

Again I’m going to talk about circadian rhythm, your internal body clock. It’s regulated mostly by the way you sleep and the way you eat, right? And it’s also regulated by day/night cycles. That’s why you naturally feel sleepy when the sun goes down and awake when it goes up.

Jet lag is such a drag because you’ll be messing up your circadian rhythm in two ways :

• Traveling several time zones will disrupt the day/night cycle
• Eating during this period, even if it’s at times when your body’s used to eat, could mess your rhythm even more

This study done on mice found out that the internal body clock seemed to be put on hold when food was scarce. Since we share our dorsomedial nucleus, that responds to hunger, with mice, this could actually also apply to us.

There’s an actual diet, used by the military, called the Argonne Diet, designed to prevent jet lag. The idea is to calculate when you’ll eat first upon arriving on destination. You’ll be alternating feasting and fasting. On the day before and the day of the flight, you’ll be fasting and breaking the fast with a regular meal at the right time at your destination.

I don’t really think you need to follow the Argonne Diet exactly, you could simply eat normally, fast for two days before and during the flight, then break your fast at the right time. If you’re used to fasting, two days is a breeze and you don’t need to feast to make it work.

Sadly, I cannot vouch for this one. Since I discovered fasting could help with jet lag, I haven’t crossed several times zones. Moreover, eating and drinking on planes is half the fun, and since I only travel for pleasure, I don’t think I’ll try it.

But if you’re a frequent flyer, give it a try! If you want to know more about this subject, I did a whole article on fasting and jet lag.

9. Help on a hangover

Being hungover is not a natural state for your body. It wouldn’t make sense to advocate fasting as a way to improve or even treat a hangover, mentioning how cavemen used to fast after a heavy day of drinking.

When you’re suffering from hungover, this means your body will be:

• Dehydrated, even though it doesn’t seem to correlate, according to this study, to the severity of the hangover
• Full of acetaldehyde, a toxic compound made by your body when breaking down ethanol
• Suffering from higher levels of inflammation through a molecule called cytokines. These molecules usually trigger fever or inflammatory responses to infection. But alcohol messes with your immune system in many ways
• In a detoxifying state, most of its energy will be put into the liver kicking alcohol out of your system

To summarize, you’ll be feeling pretty bad because the toxics leftovers from alcohol will make you feel bad and your body will take up most of your energy to detoxify itself.

Meaning fasting on a hungover really won’t prevent weight loss and fat burning since your body will have too much to do to enter ketosis anyway. So if fasting serves no real purpose weight-wise, why should you?

If you read my article on fasting on a hangover, you might already have read that I’m not especially advising that your fast on a hangover. You can, but it’ll make the day harder and I’m not sure it’ll help reduce your hangover.

But as you’ll see later in this article, fasting has powerful anti-inflammatory benefits. And some of the discomforts you’ll be experiencing on a hangover comes from inflammation.

Moreover, since I wrote the article I thought more of the way I ate on a hangover day. And I found that drinking a lot, getting out of the house, staying active and not eating for most of the day was a powerful way to recover.

Fasting alone won’t change your condition, but if I force myself to stay active, I felt way better when I didn’t eat for the whole day, than when I had a big lunch.

It might or might not be for you, but why don’t you try?

10. More focused

When you’re fasting, your body will turn to your fat stores for fuel, entering a state known as ketosis, in which your primary energy for the brain and tissue will be through ketones or ketone bodies.

What’s more, your brain prefers to get its energy from certain ketone bodies, such as acetoacetate, rather than glucose. And you know what running on ketones will do? Improve mental performances and increase focus.

This study on the effects of the ketogenic diet on physical and cognitive performance on rats found that when supplemented with ketones, rats were able to solve a maze up to 38% percent faster.

This other study conducted on mice revealed that chronic intermittent fasting improved cognitive functions and brain structure. When faced with the Barnes maze they had better learning capability and more memory.

Another side effect of fasting is that it increases brain-derived neurotrophic factor in the body, BDNF for short. This protein promotes the growth of new brain cells.

11. More energized

By now if you’ve read any articles on the benefits of fasting, you’ve seen people saying that it will give you more energy. People commonly think that they will feel tired and won’t be able to lift heavy weights when fasting.

Lack of energy can happen when fasting, mostly at the beginning if you’re implementing intermittent fasting and on the second or third day specifically if you’re doing a prolonged fast.

But once your body kicks into ketosis, meaning it starts relying on fat stores for energy, once you go past the first symptoms of fatigue, fogginess or even headaches you can experience with turning to keto, you’ll definitely feel more energized.

And think about it, our ancestors didn’t eat every day, what if on the days they couldn’t eat they felt sore, tired, unable to lift weights, run, etc.? How do you think they were able to fast several days and still go hunting and gathering food?

Our body is very strong at protecting itself and it has many important survival mechanisms. Relying on fat stores for energy, through ketone bodies and amino acids will keep you energized and most of the time, even give you more energy than getting glucose.

Remember that there is no necessary glucose, your body is perfectly able to turn fat and proteins into energy and fat stores and then turning this back to sugar for energy.

The last thing I want to mention: when you skip a meal, you’ll feel more energized for the simple reason that you won’t have to digest food. You know how tired you can get after a meal don’t you? It won’t happen with fasting.

12. Save time

Let’s get into the practical world now. I won’t be talking to you about studies or the science of time-saving. You won’t be eating, so, you’ll get more time to do something else. Pretty simple right?

You shouldn’t be fasting specifically to save time, there are hundred other (actually, more like 30+) benefits you can get from fasting, without focusing on this. But it’s a great side-effect of fasting.

I usually do 16 to 18 hours of intermittent fasting every day. So in the morning, I’m ready to start working after just one quick coffee. And if I do just one meal a day (which happens between 5 to 10 times a month for me, it’s pretty random), I’ll be saving around 1 hour more.

If you’re able to manage your hours any way you want, you can actually gain around 1h30 to 2h a day on work. You could be home sooner, spend more time with your wife, kids, exercise, pick up a passion project, start your own company. 2 hours more every day is a lot of time!

And I didn’t even talk about the amount of time saved on cooking, which could be taken into account to. We spend so much time indulging in eating. I love eating, that’s in my top 3 favorite things, but do you really enjoy your quick salad, sandwich or microwave meal that much?

13. Save money

You’ll always have enough time to fast because you don’t need to put a second of your time in it. Well, you’ll also always have enough money to do it, since it won’t cost you a dime.

At home, we usually cook a meal for dinner and we’ll reheat this meal at lunch the next day. So every day, we’re cooking for four people, even though we’re just two. If we’re not eating lunch, we’ll be saving some money.

The money-saving aspect is not that big a deal when you’re used to preparing your meal in advance like we do, a bit more carrots, a bit more chicken, etc. But imagine you’re eating out every day? Imagine you’re buying your meal every morning? That could become pretty expensive no?

Let’s say you’re just saving 2 $ a day from skipping breakfast. In a year you’ll have saved around 700 $. Imagine eating one meal a day, you could double or triple that!

Again, saving money shouldn’t be your end goal when fasting, but it is a pretty great side effect!

14. Extend longevity

It’s been known for a while now that the less you eat, the longer you live. Many studies conducted on all types of animals, ranging from mouse to yeast cells, concluded that eating less extended longevity. Depending on the animal it could even correlate: 30% less food intake meaning 30% longer life span.

So reducing calory intake, without malnutrition, meaning not only eating less but less often, affects longevity and aging in animals and humans across the board, according to this other study.

How exactly? Well, there is no clear answer. But fasting amongst other things reduces oxidative stress, improves insulin sensitivity and alters sympathetic nervous system functions. And it also promotes autophagy.

In 2016, Japanese cell biologist Yoshinori Ohsumi won the Nobel Prize in Medicine. His researches? How cells recycle and renew their content, through a process called autophagy.

In this paper on autophagy and longevity in animals, researchers conclude with :

As we described above, accumulating evidences show activation of autophagy seems essential for longevity.

There are still being unsure exactly how autophagy regulates aging, noting that timing specific roles of autophagy, cells, and tissues should also be considered.

But there is clear evidence that autophagy affects aging and promotes longevity.

15. Clear the skin and prevents acne

This 2014 update on the subject of acne doesn’t beat around the bushes:

Diet and acne update: carbohydrates emerge as the main culprit.

I don’t have access to the whole article, but the title is pretty self-explanatory. This other study implemented a low carb diet on 43 three male acne patients between 15 and 25 years old and revealed that it greatly decreased inflammatory acne lesions when compared to the control group.

Fasting doesn’t necessarily mean low-carb, but both low-carb and fasting share a side effect. It reduces insulin resistance and improves insulin sensitivity. Insulin plays an important role in acne formation and overall skin condition.

When you’re always eating carbs, your body’s always producing insulin. Insulin triggers the release of 3 hormones: IGF-1, IL-1, and IGFBP-3. These hormones block pores, producing excess skin oil and trigger inflammation.

This study conducted specifically on IGF-1 concluded that :

IGF-1 might be involved in the pathogenesis of acne by increasing both expression of inflammatory biomarkers and also sebum production in sebocytes.

Insulin effectively promotes acne and increases sebocytes formation. Sebocytes are also one of the main symptoms of oily skin.

Reducing insulin resistance and secretion through fasting or low-carb should help cure acne, clear the skin and avoid oily skin. You can also read testimonies on people reducing, or even curing, acne with this type of diet change.

16. Help promote gut balance

I already talked about how fasting could improve digestion and reduce bloating and daily bowel-movements. One of its other effects is that it will help improve gut health.

Gut health, which is also called the gut microbiome, refers to microorganisms living in everybody’s intestines. We have around 500 different types of bacteria living in there. There’s good bacteria, necessary for the body, and bad bacteria.

It has been found in the last years that gut health actually played a huge role in many other body functions: immune system, inflammation, allergies, mental conditions, autoimmune diseases, etc.

It’s even been found to have an impact on severe mental illnesses such as autism. The following review published in 2019 argues that improving gut health, through a better diet, could have an effect on the severity of the condition.

A good gut microbiome is a balanced microbiome, where good bacteria are not overwhelmed with bad ones. If you eat junk food or lots of carbs, you’ll help the proliferation of bad bacteria, which relishes on refined foods, sugars, and artificial sweeteners.

When you fast or do low-carb, you will effectively not be ingesting any food that could hurt your gut microbiome. And while you give your digestive system a break, you’ll give it time to cleanse and reset your gut flora.

And through autophagy, a process with which you should be familiar now, you’ll get many other great benefits: it’ll help the proliferation of good bacteria, clean toxins, and waste products in the gut, reduce inflammation and strengthen the gastrointestinal mucosal lining, among other things!

If you want to read a full account on fasting and gut health, check out my article on the subject.

17. Lower blood pressure

When our hearts contract, blood flow is being pushed out of the heart’s chamber. Every time it pumps or beats, it will put pressure on your body’s arteries, in order to transport blood to your tissues. This pressure is called systolic blood pressure.

When our hearts relax, the heart’s chamber is refilled with blood. This puts another pressure on your arteries. It’s called diastolic blood pressure.

So, in order to measure blood pressure, both systolic and diastolic blood pressures are going to be measured. Normal blood pressure is under 120 systolic and 80 diastolic. That’s what a doctor means when he says “120 over 80” for example.

If your blood pressure is too high, what exactly are the consequences? Well, blood flowing too strongly inside your vessels will, in the long term damage blood vessels walls, organ structures, and overall tissues. This can increase the risks of strokes, heart disease, kidney damage, etc.

Certain types of high blood pressure, or hypertension, can come from specific diseases of course. But in most cases, it’s not related to a medical issue. In most cases, it comes from what we call “metabolic syndrome”. It correlates with high visceral fat, high blood sugar and high harmful cholesterol (low HDL, high triglycerides).

Again, doing low carbohydrates or implementing intermittent fasting, will help reduce the effects of the metabolic syndrome through many other factors we will talk about in this article (lowering insulin resistance, reducing harmful cholesterol, help to unclog arteries, etc.).

Lower blood pressure will simply be a side effect of all these benefits. If you’re medicating about hypertension, I’m not by any means saying you should stop. But read about it, document yourself and talk to your doctor about it.

18. Reduce insulin resistance

To understand how you can reduce insulin resistance with fasting or low carb, let’s first see how insulin resistance actually happens in the body.

Depending on what you’re eating, your body will release some insulin. As you can see in this graph, fat consumption alone will release very low insulin, protein a bit more and carbs a whole lot more.

Released insulin will then use the food for three things, in this order:

1. To enter mitochondria and burn it up as energy (for the muscles, brain, etc.)
2. To be stored in glycogen stores in your liver for later use
3. To be turned into fat and put in your fat cells if the previous both tanks are full

When you’re eating lots of carbs every day, you’re constantly spiking up insulin levels. This means you’ll always have some insulin traveling in your blood. Even when you’re not eating, you’ll keep some excess insulin in the blood flow.

Since they’ll be submitted to insulin most of the day, your cells will grow resistant to it. Just like your body grows resistant to alcohol after a while. This means your body will become insulin resistant.

Insulin resistance is one of the big causes of metabolic syndrome and can eventually lead to high blood sugar and diabetes. When fasting, you’ll increase insulin sensitivity and reduce insulin resistance.

Since you won’t be eating, insulin levels in the blood will decrease. After a while, your cells and insulin receptors might actually increase their insulin sensitivity and even go back to normal.

Many studies have been done on the effects of fasting on insulin resistance: in prediabetic patients, diabetic patients and when compared to a regular calorie-restrictive diet. And they all show promising results on the subject.

19. Decrease “bad” cholesterol

Cholesterol markers are composed of HDL cholesterol (referred to as “good” cholesterol), LDL cholesterol (“bad” cholesterol) and triglycerides. High HDL, low LDL, and low triglycerides mean you’re in low risks of CV disease.

As I said, they’re markers. Cholesterol is not the cause of cardiovascular (CV) diseases, it’s a way to measure CV risks of a patient.

With that in mind, simply lowering bad cholesterol shouldn’t be your end goal. But through fasting, you can effectively do just that.

Triglycerides are used to transport fat in the blood and they’re then stored in the cells like that. But there’s also fat floating freely in your blood. They’re called free fatty acids and glycerols.

When you’re fasting, triglycerides will be broken down into free fatty acids and glycerols to be used for the body as energy. Triglycerides are an important source of energy in the body.

Cholesterol plays another role, it’s used to repair cells, mainly cell walls, and make certain hormones, vitamin D, and digestive fluids. So again, cholesterol is not inherently bad.

So when you’re breaking down triglycerides in the blood through fasting, oxidizing free fatty acids for energy, you’ll be lowering triglycerides levels (which is good).

I will use graphs from this study conducted on the effects of alternate-day fasting on coronary heart disease indicators to prove my point. Here’s the effect of fasting on triglycerides:

We can see an impressive 30% decrease in after 70 days of alternate-day fasting. And almost the exact same result happens in LDL levels, according to the same study:

The study describing the graphs says this :

(a) Total cholesterol decreased (P < 0.05) after 4 and 8 weeks of alternate‐day fasting (ADF). (b) Low‐density lipoprotein cholesterol decreased (P < 0.05) after 4 and 8 weeks of ADF. (c) High‐density lipoprotein did not change during the trial. (d) Plasma triacylglycerols decreased (P < 0.05) after 4 and 8 weeks of ADF.

Source

It means that after 70 days of fasting, triglycerides decreased by around 30% and LDL cholesterol around 25%. Of course, drugs, such as statins drugs, can be far more effective by reducing LDL to up to 50%. But we can achieve half of the drug’s results with simple dietary changes. Not bad!

Fasting effects on HDL cholesterol are minimal though. But that doesn’t mean it’s bad, fasting will lower triglycerides and LDL cholesterol while keeping HDL levels. I would say it’s pretty impressive.

Now we know how fasting can reduce triglycerides, but how come it also reduces LDL cholesterol? Well, when your fasting, you’ll burn fatty acids as I said earlier. Since you won’t be eating anything, your body will not create new free fatty acids, and new fat.

This decrease will then impact VLDL (very low-density Lipoprotein) secretion from the liver. VLDL is created in the liver to carry triglycerides around the body, so VLDL will reduce. And while some VLDL is cleared in the bloodstream, the rest will be transformed into LDL by enzymes.

So fewer triglycerides mean less VLDL secretion, resulting in less LDL.

20. Help to unclog arteries

In my previous point about cholesterol, I mentioned that one of its roles was to repair cells, mainly cell walls.

When a blood vessel or arteries suffer from cracks or lesions, cholesterol will come to the rescue and, coupled with calcium, it will create plaques to “heal” the damaged organ.

What’s crazy is that this natural healing process coming from your body itself is actually the root cause for arteries clogging. When blood vessels constantly suffer from inflammations or cracks, calcium plaques will accumulate, resulting in clogged arteries.

What causes the lesions at first? You might say high cholesterol, you might say too much fat.I would have said that too a while ago.

But it’s actually insulin resistance, low vitamin C and high blood pressure, all coming mostly from high carbs, especially sugars, diet.

If you an to know more about the science behind this, you can take a look at my complete article on the subject of fasting and arteries clogging to know more.

The idea behind fasting being able to unclog arteries, is simply that, again, it will increase insulin sensitivity. If you’re not eating, you’re not producing insulin, you’ll have lower insulin levels and after a while, insulin resistance will reverse.

Simply because your cells won’t be exposed to insulin 24/7 anymore. Insulin sensitivity will increase and blood pressure decrease.

As for vitamin C in the complex (not pills or synthesized vitamin C, but the one found in fruits and vegetables) depletion, that could also have an impact and you should combine fasting with a healthy diet, of course.

Reducing insulin resistance and blood pressure through fasting will help reduce lesions and inflammations of the blood vessels and arteries. Fasting to unclog arteries is a big first step, check out my article to see other things you can do in order to help reverse this condition.

21. Help against metabolic syndrome

Suffering from metabolic syndrome means you’re at risk of developing heart diseases, stroke, and diabetes. This usually comes as an aggravation of insulin resistance and other risk factors.

Metabolic syndrome also means hypertension, high blood sugar, excess visceral fat, abnormal cholesterol, and triglycerides levels. As you can see, we’re always circling around the same problems. And all these conditions are interlinked.

Meaning implementing fasting will help increase insulin sensitivity, it’ll decrease triglycerides and LDL cholesterol, decrease blood pressure, help with arteries clogging, and make you lose weight.

In this study, they stated that simply implementing 10-hours restricting eating window (meaning 14-hours intermittent fasting), when combined with traditional medication, was enough to reduce abdominal fat, increase weight loss and lower blood pressure and cholesterol.

Since metabolic syndrome comes from excess fat in the body, excess sugar and carbs consumption, fasting can effectively help reduce all this. As always, combined with healthy eating habits it will do marvels.

22. Reduce risks of a cardiovascular event

A study was conducted between 2004 and 2006 on 448 Mormon patients. The purpose? See how fasting, which is part of their religion, impacted their heart health. They saw that fasting regularly was reducing the risks of coronary disease by 50 to 60%. But the fact that Mormons also restrict from tobacco definitely has an impact on the results of this study.

I could also refer back to this study I mentioned earlier, where cardiovascular disease risk diminished by simply implementing a 10-hour eating window. Intermittent fasting for short.

Again, through the reduction of triglycerides and cholesterol levels, decreased blood pressure, coronary heart disease risks will lower and heart health will get better.

Check out this study on the effect of a three-weeks fast on extremely obese patients or this study on the impact of implementing fasting in your everyday life in order to reduce risks of coronary heart diseases and diabetes.

23. Help keep a healthy liver

Fasting is known to help liver health, especially to prevent conditions like fatty liver diseases. While this is known, exactly how fasting was able to help this condition wasn’t known until recently.

First, there is this 2016 study in which they found that upon food deprivation, a certain type of protein in the liver, called GADD45β, was produced to adjust the metabolism in the liver.

The greater the hunger, the more of this specific protein secretion in the liver. This protein seems to be responsible for controlling the absorption of fatty acids in the liver. In the study, mice who lacked the corresponding gene were more at risk of developing fatty liver disease.

But when the protein was restored, through fasting, which is putting stress on the liver that stimulates GADD45β production, fat content in the liver normalized and sugar metabolism improved.

The study not only was able to see this happening on mice, but this effect was also confirmed in human beings: low GADD45β levels are accompanied by increased fat accumulation in the liver and elevated blood sugar levels.

Another recent study, conducted in 2020, saw that intermittent fasting was able to change liver enzymes. Especially another protein called HNF4-(alpha) which seems to get inhibited through fasting.

This impacted blood protein levels in inflammation and bile synthesis. Which in turned proved to change fatty acids metabolism in the liver for the better.

While the study states that this discovery could lead to the creation of new medicines, they conclude that this new information can be used in future studies to determine the best fasting periods to impact protein responses in the liver.

24. Reduce oxidative stress

Oxidative stress occurs when unstable molecules, known as free radicals, are produced in a higher-than-normal manner. Free radicals carry highly reactive electrons and when reacting with other important molecules (such as proteins or DNA), they’ll damage them.

Oxidative stress can be caused by many things:

• Smoking
• Disruption of the circadian rhythm
• Psychological stress
• Infection
• Inactivity
• etc.

The problem is that constant oxidative stress can lead to important oxidative damage in your cells, promoting aging and chronic diseases.

There have been quite a few studies on the subject of fasting and its effects on oxidative stress, all leading to the same conclusion: it’ll help enhance resistance to oxidative stress.

As for how it is still a bit unclear, but the fact that fasting is promoting autophagy is a pretty good lead. In this study on the effect of autophagy on oxidative stress and DNA damage, we can read the following in their conclusion:

Autophagy is able to limit cellular damage through the maintenance of energy homeostasis, oxidative stress reduction, and elimination of damaged proteins and organelles

So, fasting promotes autophagy which in turn limits cellular and DNA damage through reducing oxidative reduction. What’s more, this process will also replace and recycle damaged cells.

25. Reduce inflammation

Inflammation is not a villain, it’s triggered when your body needs to fight body infections. But as we also know, too much inflammation in the body is bad and it can help lead to various diseases and conditions such as cancer, heart, disease, asthma, type 2 diabetes, obesity, etc.

One of the causes of too much inflammation in the body is the way we eat. We eat too much and too often.

This study conducted in 2019 had patients not eating between 12 and 3 p.m. on the first day and between 8 p.m. on the same day and 3 p.m. the next day. On both days, they took blood samples at 3 p. m. to test white blood cells.

White blood cells are known as protection against infection. Typically, white blood cell levels in the body indicate levels of inflammation. They especially took a look at specific cells that cause inflammation called monocytes.

What they discovered is that between the two days, the two samples showed a strong drop in monocytes.

The conclusion to the study is not that you should fast or starve yourself to reduce inflammation, it’s more that people eat too much and too often on an everyday basis which causes high levels of inflammation in the population.

This other study from 2019 indicates that intermittent fasting was able to reduce another pro-inflammatory protein called cytokine.

And there are other studies on the subject of inflammation and fasting, all resulting in the same conclusion that eating less and, more importantly, less often will reduce overall inflammation in the body.

26. Reduce anxiety and depression

Before talking about fasting, I would like to address depression and how it manifests, based on many studies, for you to understand how any type of fasting could help.

As I said in my previous point, when you’re sick, your body will trigger inflammation. The purpose of inflammation is to fight the infection. As a result, you’ll feel tired, in a bad mood, you’ll suffer from sleeping and eating disorders, you won’t have the energy or motivation to do anything, etc.

Those are not side effects of the infection itself, they are side effects of increased inflammation in the body. As you can see, the symptoms of inflammation I just described, are pretty close to the way you feel when you’re depressed.

That’s because when you’re depressed, you actually have higher body markers for inflammation by up to 50%. The risk of depression actually increases with the risk of inflammation.

Various studies tested correlations between depression and inflammation. In this study, when injected with an inflammation-inducing substance, patients showed greater increases in a depressed mood, feelings of social disconnection and inability to feel pleasure.

Another condition that puts you at a higher risk of depression is obesity. The higher the body mass index, the higher the risks of depression. But also higher BMI, means higher inflammation according to this study.

Because fat adipose tissues are actually known to produce pro-inflammatory cytokines (which I mentioned in my previous point). This other study suggests that the link between metabolic syndrome and depression could be inflammation.

I know, in many cases depression doesn’t come from your diet or sleep habit, but from a tragic life event, a trauma, etc. And that’s perfectly right, it can come from any sort of psychological stress.

Again, psychological stress is a known trigger for inflammation. In this study, mice were stressed with isolation and it revealed they secreted an increased amount of cytokines.

This other study conducted the Trier social stress test on patients. It revealed a 2 to 4 times increase in cortisol (the stress hormone) and also an increase in plasma concentration (IL-6) of inflammatory cytokines.

To end this exposé on inflammation and depression, let’s ask ourselves why stress would put our body in a state of inflammation. For that, we must go back to our hunters-gatherers ancestor: they only experienced stress when in danger of being wounded or killed (animals, other tribes, meteorological events).

So the body could have originally triggered inflammation as a way to prepare itself to fight infection. If stress = wound or infection, then stress = increased levels of inflammation.

To end on this subject, how does fasting enter the mix? Well, as I mentioned in my previous point, fasting can help fight inflammation. On the contrary, eating too much and too often promotes inflammation.

27. Increase growth hormone secretion

Contrary to certain believes, fasting won’t shut down your body. When you’re fasting, counter-regulatory hormones such as adrenaline, noradrenaline, and cortisol will be released, in order to keep your body ready for action.

Another counter-regulatory hormone is also released during a fast: growth hormone. Growth hormone secretion increases by 2 or 3 times on the first day of fasting and put to the fifth day.

Those higher than-normal secretions mostly come as a direct response to insulin levels dropping in the body. Which means when you break your fast, your body will have spiked up growth hormone during this time. And breaking the fast will spike up insulin which, combined with growth hormone, will promote protein synthesis.

Meaning when your fast, you prepare your body to be more efficient at muscle growth, through protein synthesis. Check out my complete guide on fasting and muscle growth to know more.

Other benefits of high secretion of growth hormone include:

• Improved lean body mass
• Increased bone density
• Increased skin thickness
• Promoting weight loss
• Better mood, cognitive functions, and better sleep

28. Burns Fat And Promotes Weight Loss

Yes, I’m really going to talk about burning fat with fasting because when I say complete list, I mean complete list! If you have any interest in fasting, you will already know how this works. But I’ll summarize the process anyway.

When you’re fasting, meaning you restrict not the amount you eat but when you eat, your body will find himself depleted of glucose to run on since it usually relies on the ones you’re ingesting.

Ingested glucose, proteins and fat are either used for energy right away, stored in glycogen stores in the body (liver, muscles, etc.) and, if all of the stores are full, stored as adipose tissue, fat, in the body.

If you don’t eat for a while, your body will tap into your glycogen stores first for energy. Think of it as your fridge. Need some energy? Just get up and get to the fridge, where you stored stuff for immediate consumption.

What happens when glycogen stores, the fridge, is empty? Well, your body is pretty smart, it stored a lot of energy in the form of fat all-around your body. We’ll call that the cellar. Except as smart as the body is, it’s also pretty lazy.

I shouldn’t say lazy, I should say it’s used to simply go to the fridge or get fed right away. And your body is also really good at saving energy, going to the cellar, turning body-fat into energy, consumes energy and if your body is not used to doing that, it won’t happen right away.

Fasting, by depleting energy stores, will force your body’s whole machinery to turn to fat for fuel instead of glucose. This state is known as ketosis. In this situation, your body will turn fat into ketone bodies as fuel for the brain and break down fatty acids and amino acids in your body as energy for the whole body.

Fasting will make you use your fat stores as energy. The more you’ll do it, the more you’re metabolism will get used to doing it, the easier it will get, the faster your metabolism will be, the more fat you’ll lose.

29. Preserves Muscle Tissue

While we’re talking about burning fat, you might wonder if fasting would also burn muscle. One possible cause of muscle loss is starvation. And you might think fasting is a form of starvation, but it really is not.

Low calory diet, meaning voluntarily inducing fewer calories intake that your body actually needs every day, while eating 3 to 5 times a day, that’s a form of starvation. Here’s a definition of low calory diet I found on Healthline :

What people generally refer to as “starvation mode” (and sometimes “metabolic damage”) is your body’s natural response to long-term calorie restriction. It involves the body responding to reduced calorie intake by reducing calorie expenditure to maintain energy balance and prevent starvation.

Source

Take a look at this study on low calory diet, exercise and muscle loss. On this type of diet, even when you’re actually exercising, you will lose muscles. In starvation mode, your body will try to reduce energy expenditure, since it’ll think you’re in an environment where food is scarce.

Muscles being very energy costly, the body will eventually start breaking it down in order to match energy expenditure to your caloric intake.

When you’re fasting, you’re actually eating less frequently, kind of like our ancestors were and your body is used to relying not only on the food you consume but also on ketone bodies and fatty acids in your body. Your fat stores.

Here’s an example of a study conducted on patients doing alternate day fasting for 70 days. They measured lean body mass (bones, muscles, etc.) every day. Do you know what they discovered? It didn’t change one bit.

The single worst thing you can do which will make you lose muscle is to be sedentary and don’t exercise. Implementing fasting or even low carb won’t cause any muscle tissue to get broken down. None.

If you want to know more on the subject of muscle and fasting, check out this beast of an article that I wrote on the subject.

30. Boost Your Metabolism

I talked about it briefly when mentioning weight loss, but one of the great benefits of fasting is that when done regularly it’ll improve your metabolism. What exactly does “boosting the metabolism” means?

The metabolism is not an organ, it’s everywhere in your body. It refers to a multitude of chemical processes that occurs in your cells. The main purpose of your metabolism is to turn calories to energy.

Your body’s efficiency at burning calories for energy is what we call the metabolic rate. This measure will vary from one day to another, depending on your activity level. Basal metabolic rate, meaning the number of calories needed for your body to properly function (blood circulation, breathing) stays fairly steady from day to day.

You certainly have heard (or even tried) about someone who did a calory restricted diet for a while, achieved their goals and when they started eating normally again, regained all the weight.

This is because a calory restriction diet slows down your metabolism. Your body is trying to preserve energy stores because it thinks you’re in a place where food is scarce. sYou eat 3 to 6 times a day, never to satiety, and you end up with fewer calories than

31. More weight loss in the abdominal cavity

When we’re trying to lose weight, especially men, we often obsess about belly fat. We also amusingly calling that the “beer belly”. And it is, visceral fat generally comes from fat forming around the organs, it is not a natural process in the body.

But through alcohol or refined carbs and sugar metabolization in the body, check my article on alcohol and fasting for the whole process, visceral fat will accumulate. It’ll also promote fatty liver, but that’s another story.

So how fasting can help reduce visceral fat? Well, it’s not specifically that it targets visceral fat, it’s more that losing visceral fat is harder than other types of fat, and fasting is good at it.

To be a bit more “scientific” about it, fat cells have 2 important receptors :

• Alpha-2: They will prevent fat burning. These receptors tell the cell to store fat for later use
• Beta-2: Those will promote fat burning by telling the cell to release the fat inside into the bloodstream

One of the effects of fasting as I already stated is that it will increase insulin sensitivity and reduce insulin levels in the body. And one of the side effects of low insulin is that it will inhibit alpha-2 receptors and activate beta-2, this means it will promote fat burning.

What’s interesting to know is that the abdominal cavity contains more alpha-2 receptors than elsewhere in the body. Which explains why it is so hard to burn visceral fat.

But with this ability to activate beta-2 receptors and shut down alpha-2 receptors, through low insulin levels, burning belly fat is made possible, and efficient, through fasting. Low-carb diets will have the same effect.

32. Never Worry About Your Weight Again

Are you ready? Okay, if you experiment with fasting and if you’re able to implement it in your life through any type of intermittent fasting or through prolonged fast: you will never have to worry about your weight again.

You will never have to worry about your weight again!

I’ll let that sink in for a bit, but to me, it is the single most important benefit I get from fasting. I’ve never been obese, I discovered fasting when I was around 30 pounds fatter than I am now.

And I didn’t lose 30 pounds in six months, I did it in around a year. I wasn’t in a hurry, I implemented 18 hours intermittent fasting every day and did 6 days fast in the middle and there you go.

Now that I’m used to doing that, I never worry about my weight. Maybe I’ll gain some over Christmas, but it’ll eventually go away and if I want to boost the process I can always do one meal a day for a while.

Because it’s that easy.

When talking with people I always hear “I cannot do that it would be too hard”. And every time someone I know tried it, they were able to implement 18 hours intermittent fasting in 2 to 3 weeks tops.

As I always say to people interested in fasting, you don’t have to go all-in right away.

Start with eating less at breakfast, maybe delay it by an hour, just do it progressively. I know it can be really hard depending on your condition, but as hard as it may seem at first, you’ll see that it gets a whole lot easier.

Once you’ll be able to not eat for a whole day you’re done. You’ll be able to experiment with several days fasts too. If you know you can do it, you’ll realize you can control your weight easily.

Even if you’re obese, once you can do one meal a day routine, you’ll see those pounds disappear a little bit more every day. And as I went over and over in that article, it’s really not just about weight, but also your health.

You’ll eventually end up like me, never having to worry about your weight again. Coupled with more than 30 other potential life and health benefits, you have no excuses!

WHAT IS PROLONGED FASTING | BENEFITS | SIDE EFFECTS | WHO SHOULDN’T DO PROLONGED FASTING | HOW TO DO PROLONGED FASTING

Prolonged fasting, extended fasting or water fast… What are the benefits?

All of these terms are synonyms for the same thing – a seemingly simple process of not eating for an extended period. Usually, it means no food intake for anywhere from 24 hours to multiple consecutive days.

You might be asking: Why would you choose to “starve” yourself for days? Is prolonged fasting safe? What prolonged fasting results should you expect? 

And can we even survive without food and how long can you safely fast?

We’ll dig into this and more below, so keep reading.

What is prolonged fasting and how long can you safely fast?

Fasting is natural to us. Or at least it used to be…

Fasting has been part of human nature since the beginning of time. Until relatively recently, food was not so readily available. To survive, early humans needed to store energy from food as body fat to survive the times when food was scarce. If the human body did not have an efficient storage and retrieval method of food energy, we wouldn’t have survived until now.

When it comes to fasting length, if you’re a healthy person (with some exceptions, check here), you shouldn’t worry that a few days without food will starve you. The longest-lasting hunger strike in recorded history was undertaken by an Irish political prisoner, Terence MacSwiney. He went for 74 days with no food. Disclaimer… it did not end well for him.

Nevertheless, an average person nowadays is accustomed to regular meals and our bodies are not used to no-food-days anymore. Therefore, we strongly suggest limiting your prolonged fast to a maximum of 72 hours and undergo longer fasts only under medical supervision.

Why would people even put themselves under this challenge of giving up one of the greatest pleasures in our lives – food?

And do it voluntarily for hours…or even days?

Here’s what science says about some of the benefits of prolonged fasting and the prolonged fasting results you could expect.

Prolonged Fasting Benefits

Extended fasting for weight Loss

Your body is designed to have two different states: “fed state” and “fasting state”.

In the fed state, when you are regularly eating, insulin levels are high. During this time, it makes sense to derive the energy from the food that you are eating and store excess calories in your fat cells.

In the fasting state, insulin levels fall. This is the signal for your body to switch energy sources from food to stored body fat from your fat cells and start burning it for energy. 

As each of our bodies works differently, the time needed to reach ketosis also varies. On average, your body will start burning ketones after 8-10 hours of fasting. However, it can be accelerated by exercise or following low-carb a.k.a. Keto diet before starting the fast.

Bear in mind you will also be skipping around 1500- 2000 calories each day you’re fasting. This means fewer calories for your body to burn, promoting weight management or weight loss.

Just make sure you don’t overcompensate for these lost calories during your periods of eating. A healthy, balanced diet is the key to feel and look your best, no matter what the numbers on a scale say. 

Fasting has also shown to increase metabolic rate by 3 – 14%, which translates to an additional 100 – 275 calories burned daily. This effect seems to diminish if you’re fasting longer than 72 hours.

However, while prolonged fasting could result in a few pound weight loss each fasting time, prolonged fasting for weight loss might not be the best long term weight loss strategy. It is not advised to do prolonged fasting more than once or twice per month; therefore some other types of time-restricted eating might be a more sustainable weight-loss strategy.

For example, intermittent fasting 16/8 where you fast for 16 hours and have an 8-hour eating window each day has proven to be an effective long term weight loss strategy. Particularly if you also make sure to have a healthy, balanced diet that fits your weight goals. 

If this pricks up your ears, check out this 21-day Intermittent Fasting 16/8 challenge that comes with a personalized meal plan. In 21 days you will be doing healthy intermittent fasting like a PRO.

Promoted longevity

Fasting activates autophagy – a process critical for cell health and renewal. During autophagy, cells destroy viruses and intracellular  bacteria and get rid of damaged structures.

No need for juice cleanses and detox diets, autophagy (the word literally means “self-eating”) is your body’s natural way to do a cleanse.

While there aren’t large human studies done to determine the effects on fasting on life expectancy. A major study on monkeys shows that strict, low-calorie-intake diets could be the key to having a longer, healthier life. Monkeys on calorie-restrictive diets not only lived longer but also had fewer incidents of cancer and cardiovascular diseases.

Mental health benefits

Many people undergo prolonged fasting due to various mental benefits. It can improve your relationship with food, help appreciate it more or break free from patterns of emotional eating. 

However, people with previous eating disorders should be very cautious with any type of fasting as it might have the opposite effect and trigger the old patterns of unhealthy eating habits.

Fasting is part of many religions and spiritual practices and is often practiced to experience increased gratitude, develop self-discipline or even strengthen the faith. The idea is to deny your body its physical needs in order to move the focus away from your body and toward your faith and spirituality.

While it might sound contradictory, often extended fasting supporters report feeling more productive, energized and focused during their fast. 

For example, an American entrepreneur and author Tim Ferris practices a 4-day monthly fast that typically begins on Thursday night and ends on Sunday night. As the productivity expert himself says, he normally experiences “some very very clear cognitive benefits,” including more energy and focus.

Side effects of prolonged fasting

Obviously, it’s not all fun and games when it comes to drastically changing your eating pattern. After all, your body has been used to your current eating habits which most likely didn’t involve starving it for hours and possibly days.

In a study with 768 people fasting for at least 48 hours, 72% of participants reported at least some side effects with the most common ones being hunger (surprise, surprise), fatigue, trouble sleeping, and dizziness.

Extended fasting tips: How to ease side effects of prolonged fasting?

Here are 3 important tips to lessen the side effects of prolonged fasting:

• It is particularly essential to ease into long fasts. For example, try less demanding fasting schedules to prepare your body and mind for what’s to come with prolonged fasts.
• Many of the side effects can be diminished by staying hydrated. Take into account that approximately 20% of our water intake comes from food, therefore add a few more glasses to your recommended water intake. Another reason to drink enough water? It is proven to reduce hunger…which is a huge benefit for anyone fasting.
• Make sure to have enough sleep, feel free to fight hunger or sluggishness with zero-calorie beverages like plain tea or black coffee and don’t wear yourself out with heavy exercises to minimize the side effects of the extended fast.

Who shouldn’t do extended fasting?

While for most healthy people prolonged fasting (up to around 72 hours) poses little health risks, you should consult with a doctor before starting any fasting, especially extended fast, if you.:

• Are underweight (BMI under 18.5) or struggling with weight gain. You won’t be consuming (or severely restricting) calories for 24 or more hours which definitely won’t be helpful for weight gain. Additionally, being underweight can heighten the side effects like dizziness, fatigue and others, as your body, is more sensitive to calorie restrictions.
• Are pregnant or breastfeeding. Most likely, this won’t be the time to try out most types of fasting, especially the more drastic ones like extended fast.
• Are under 18 years old. Effects of fasting during periods of rapid growth, such as for children and teenagers, are not studied enough; therefore, you should be cautious with it. Moreover, insufficient nutrition during childhood and teenage years can cause growth retardation and hypogonadism.
• Have suffered from an eating disorder. Restricting times of eating can increase the risk of falling back into old habits during an eating disorder.
• Have type 1 diabetes. Fasting increases the risk for hypoglycemia and raises sensitivity to insulin, therefore it may affect how much insulin medication you need.
• Have gastrointestinal disorders incl. ulcers and gastritis.

Most importantly, remember the good old saying “listen to your body”. Don’t push past your limits and know how to stop when it just doesn’t feel right to keep going. 

Fasting, especially for an extended period of time, is not for everyone.

How to do prolonged fasting 101

How to best prepare for an extended fast?

Remember, you’re up for a mental and physical rollercoaster ride.

There will be both periods of sharp focus and extreme sluggishness. Some moments all you can think of will be food or you might be overwhelmed with the infamous “hanger” (a combination of feeling hungry and angry). Therefore, if possible, for fasting pick days without potentially stressful and demanding activities planned. 

If you are new to fasting, especially prolonged fasting, it would be a good idea to spend 3 to 4 days preparing your body for the extended fast. Some ways to do so:

• Eat smaller portions at each meal
• Reduce your daily caloric intake
• Opt-in for intermittent fasting. For example, try intermittent fasting 16/8 with 16-hour fasting and 8-hour eating window to make your body used to time-restricted eating.

What to do and drink while fasting?

1…2…3…stop eating.

Sounds easy right? Still, there are certain important things to note during your fasting time. 

Firstly, as mentioned before, stay hydrated! Normally you should follow the rule of 8×8 (8 glasses of eight ounces of water); however, during fasting time it is important to drink even more as you are not intaking water from food.

What exactly can you drink during prolonged fasting?

Your safe drinks with zero calories are:

• Water (any kind: carbonated, mineral, hot, cold and so on)
• Black coffee
• Plain tea

For more in-depth fasting drinks guide, check “What Can You Drink During Intermittent Fasting”.

If you choose to stick with strict fasting, you shouldn’t consume any food or caloric beverages. However, if a splash of milk in your coffee, a cup of light broth or water infused with fruits/cucumber/mint changes your fasting experience from unbearable to doable, feel free to do it. Some fasting experts, for example, Berkhan from Leangains, allow to consume up to 20 kcal during the fasting period. 

How to break the prolonged fast?

While it might be tempting to binge on food right after the fast is over, it is crucial to reintroduce food slowly.

Yes, it might be even dangerous to follow your urge to eat a huge meal. 

This is because you may be at risk of refeeding syndrome, a potentially lethal condition in which the body undergoes rapid changes in fluid and electrolyte levels as it digests and metabolizes food after a long period of not eating.

The best is to break your fast with a small meal, smoothie (click for some healthy smoothie tips), light soup or salad. As you feel more comfortable, you can start introducing larger meals throughout the day. For longer fasts, it might even take a few days to feel completely comfortable eating a large meal.

Oh, and hope you’re looking forward to another prolonged fasting benefit: you will have a completely different appreciation for food! Nothing compares to the flavor of food you’ve been craving for days.

Is there anything I can eat that Mimics Fasting?

The only products I have heard of that can Mimic fasting and maintain some benefits to fasting are the ProLon Meal Kits. Discovered and developed at the Longevity Institute of the University of Southern California, the technology is plant-based nutrition that allows the body to enter into a beneficial fasting state without triggering the cells’ nutrient sensors. As the name suggests, it actually mimics fasting…while still allowing you to eat food. This nourished fasting fine-tunes cells, supports healthy aging, and eliminates the need to do a water-only starvation fast, which can have negative side effects. Get the ProLon Products Here.

So, should you try prolonged fasting?

Now when you have read about all the pros, cons, to-dos and dont’s of prolonged fasting, it’s up to you whether it sounds like something worth trying.

While it’s often fun and even confidence-boosting to test your mental and physical limits, remember to take care of yourself and don’t exceed your limits. When in doubt, consult with a doctor.

Want to snack while fasting without losing the benefits of a fast, check out the ProLon Fasting and Reset Meal kits.

Need an APP on your Mobile to help with Fasting? See our Top 6 FREE and Premium Fasting Apps

Want to go on a Fasting or Health retreat with likeminded others?  Check out our Fasting Retreats review page Here.

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What is fasting?

Fasting is a powerful spiritual discipline. Through fasting and prayer, the Holy Spirit can transform your life. And the practice of fasting has strong roots in the Bible. Jesus himself spent time in fasting and prayer during his life on earth, and he expected his followers to fast as well. Most commonly, fasting is when you abstain from food or a certain type of food for a period of time. However, there are multiple ways to fast, all with the potential to help you grow spiritually.

It’s important to ensure you’re listening to both the Holy Spirit and your own body in the way you fast. Instead of abstaining from food altogether, you may fast from a particular type of food or even something other than food, such as social media. You might decide to fast until a certain time in the day or skip a certain meal. There are many ways to ensure you’re getting the physical nourishment you need while still enjoying the spiritual nourishment fasting and prayer offer.

Fasting and prayer can also bring about more than just personal transformation. When God’s people practice fasting and prayer, God hears from heaven and can heal our lives, our churches, our communities, our nations, and our world. Fasting and prayer can even bring about revival—a change in direction.

Fasting in the Bible

Fasting was an expected spiritual discipline in both the Old and New Testament. In fact, we see examples of fasting in the Bible from several significant biblical figures. Moses, for example, fasted at least two recorded 40-days periods (Deuteronomy 9:18-19, Exodus 34:28). Jesus also fasted for 40 days and nights (Matthew 4:2). 

If 40 days seems like an impossible amount of time to survive without sustenance, that’s because without divine intervention, it is. (Humans can only last about three days without water.) But biblical fasting didn’t usually mean going without food or drink 24/7. The Jewish custom was to fast during the day but eat and drink as soon as it was dark. 

Jesus encouraged in his followers an intentional approach to fasting as a spiritual tool, not a biblical law. When a Pharisee questioned Jesus about why his disciples weren’t fasting like the Pharisees, he offered his own guidance on the role of fasting. Comparing his disciples to guests at a wedding, Jesus said, “The wedding guests cannot mourn as long as the bridegroom is with them, can they? The days will come when the bridegroom is taken away from them, and then they will fast” (Matthew 9:14-16). This guidance can still apply to us today. When we feel far from God, fasting can help us mourn our distance from God and draw closer once again.

Why should you fast?

According to Dr. Bill Bright, who produced a guide to fasting for cru.org, there are a number of reasons why the practice of fasting can be spiritually beneficial. 

• Fasting is biblical. We see examples of biblical fasting in the lives of figures like Moses, Jesus, and King David. 
• Fasting and prayer can restore or strengthen your intimacy with God. Many longtime Christians find that fasting helps them rediscover their “first love” for God again.
• Fasting is a way to humble yourself in the sight of God (Psalm 35:13; Ezra 8:21). King David said, “I humbled my soul with fasting” (Psalm 69:10). You may find yourself relying on God more fully for strength when you fast.
• Fasting and prayer can help us hear God more clearly. To listen to God as you fast, consider combining a time of fasting with a practice of listening prayer. Together, fasting and prayer can transform your prayer life into a richer and more personal experience of God.
• Fasting enables the Holy Spirit to reveal your true spiritual condition. When you see your own brokenness more clearly, you’re able to move toward repentance. 
• When you experience revival in your own life through fasting, the grace and love of God can shine through you into the lives of others. 

Types of fasting

According to pastor and author Sam Storms, there are several different types of fasting from food or drink you can try. 

Regular fast: A regular fast is when you abstain from all food and drink except for water (Matthew 4:2).

Partial fast: This is a type of fasting that involves abstaining from a particular type of food. Daniel’s diet while he was in Babylon is an example (Daniel 10:3). One popular type of partial fast is a liquid fast, removing certain types of drinks from your diet. This might include alcohol, caffeine, or soda. Another form of partial fast is abstaining from one particular meal each day. 

Absolute fast: An absolute fast is when you abstain from food and drink of any kind. You should only do this for a short period of time. Going longer than three days without eating or drinking can be dangerous.

Supernatural fast: There have been instances when God enabled someone to fast in ways that they could not do on their own. Moses abstaining from food and water for 40 days (Deuteronomy 9:9) is an example of this type of fasting in the Bible. 

Spiritual preparation for fasting and prayer

In preparation for this special time with God, cru.org’s guide to fasting urges that you examine your heart. Ask God to help you see your brokenness clearly so that you can confess your sins and repent. In Scripture, God frequently calls upon people to repent of their sins before listening to their prayers. 

You can look to King David’s example in Psalm 66:16-20:

“Come and hear, all you who fear God,
    and I will tell what he has done for me.
 I cried aloud to him,
    and he was extolled with my tongue.
If I had cherished iniquity in my heart,
    the Lord would not have listened.
But truly God has listened;
    he has given heed to the words of my prayer.

Blessed be God,
    because he has not rejected my prayer
    or removed his steadfast love from me.”

In your prayers, confess not only obvious sins, but less obvious ones as well. Acknowledge the sins of omission (the right actions you haven’t taken) as well as the sins of commission (the wrong things you’ve done). What is standing in the way of your relationship with God? What is holding you back from living and loving like Jesus? It might be self-centeredness, spiritual indifference, an unwillingness to share your faith with others, putting time spent in prayer and study of God’s Word low on your priority list, or struggling to love your neighbors and treat them with kindness. Confess your shortcomings and ask God to work in your heart during this time of prayer and fasting.

Your motive in fasting should ultimately be to glorify God, not to have an emotional experience or attain personal happiness. God will honor your seeking spirit. As you spend time in fasting and prayer, God will shape your heart and draw you closer to Christ. 

How to fast safely

Fasting can be practiced safely. However, as you begin a time of fasting and prayer, friends and family may express concerns about how fasting could impact your health. And they are right to encourage you to safeguard your health. It may be a good idea to consult with your doctor before you begin a time of fasting and prayer. If you struggle with certain medical conditions, such as an eating disorder or being chronically underweight, you should not fast without the supervision of a health professional. In some cases, fasting from something other than food may be a better option. 

But when practiced properly, fasting can be both a spiritual and physical blessing. In fact, a growing number of people have begun to practice intermittent fasting for its dietary benefits. Here’s a guide to safe intermittent fasting from Johns Hopkins with some helpful tips for fasting safely.

Safe fasting tips and guidelines:

• Fasting until a specific time of day or skipping a specific meal each day is safer and more sustainable than a complete fast. For a fast that will be longer than 1-3 days, this is often a good option.
• Consider fasting from a specific type of food instead of all food, especially if you want to fast for a long period of time or have health concerns.
• A complete fast should be very short; it should not last longer than a few days.
• Do not abstain from drinking water for long and only do so under your doctor’s supervision. The effects of dehydration are serious, and your body may begin to experience them more quickly than the effects of hunger. 
• If fasting from food or drink isn’t a good option for you, you can still practice fasting. Choose something else in your life to fast from instead. For example, consider fasting from TV or social media.

Grace Ruiter

Grace Ruiter co-founded Faithward and oversaw its growth from a small blog to a ministry that reaches 100,000-200,000+ people each month. She has been asking too many questions ever since she started talking, and she has no plans of stopping now. Although her curiosity has challenged her faith at times, it’s also how her relationship with God has grown to where it is today. You can get in touch with Grace at graceruiterwrites@gmail.com.