If you’re wondering, “How, or why, should I fast?”, then look no further. I have had a lot of experience in fasting.
This post contains the following sections on Fasting.
- What is the Purpose of Fasting?
- What is it like to Fast?
- The Spiritual and Psychological Effects of Fasting
- Physiological Effects of Fasting
- What Should I Eat and What Should I Not Eat?
- How Long Should I Fast?
- My Anecdotal Experiences in Fasting
- Biblical and Current Information About Fasting
- Conclusions from Isaiah
You will have to decide the answers to these questions for yourself. But I will offer some information here that has helped me decide when, how, and how long to fast. I hope this gives you some helpful insights as well.
What is the Purpose of Fasting?
First of all, fasting should be done privately, or in conjunction with others who are also fasting. Fasting should never be done publicly for the purpose of receiving recognition for our “spirituality”. Jesus speaks towards this specifically in Matthew 6:16-18.
“Moreover, when you fast, do not be like the hypocrites, with a sad countenance. For they disfigure their faces that they may appear to men to be fasting. Assuredly, I say to you, they have their reward. 17 But you, when you fast, anoint your head and wash your face, 18 so that you do not appear to men to be fasting, but to your Father who is in the secret place; and your Father who sees in secret will reward you openly.
Secondly, I do not encourage anyone with physiological motives to fast. The Bible is clear that fasting is helpful from a spiritual perspective, and the motive should be to enhance the quality of ones’ relationship to God.
Jesus talked about fasting in Matthew 9:14-17, Mark 2:18-22 and Luke 5:33-39. In all three passages, Jesus emphasized that people will fast “when the bridegroom” (Jesus) will be taken away from them”. It is implied that fasting will strengthen a person in spirit during a time of trials, or when God seems “distant”.
33 Then they said to Him, “Why do the disciples of John fast often and make prayers, and likewise those of the Pharisees, but Yours eat and drink?” 34 And He said to them, “Can you make the friends of the bridegroom fast while the bridegroom is with them? 35 But the days will come when the bridegroom will be taken away from them; then they will fast in those days.” 36 Then He spoke a parable to them: “No one puts a piece from a new garment on an old one; otherwise the new makes a tear, and also the piece that was taken out of the new does not match the old. 37 And no one puts new wine into old wineskins; or else the new wine will burst the wineskins and be spilled, and the wineskins will be ruined. 38 But new wine must be put into new wineskins, and both are preserved. 39 And no one, having drunk old wine, immediately desires new; for he says, ‘The old is better.’”
Also, each of these three passages is followed by the parables of the Patches and the Wineskins. A lot of speculation has surrounded the interpretation of these parables, but I want to offer up my own understanding of these parables. To do so, let me first briefly describe the experience of fasting.
What is it like to Fast?
During the first few hours of fasting for the first time, one is naturally and constantly faced with the desire to eat. For some people, enduring this desire and denying themselves the satisfaction of eating is a tortuous task of significant magnitude. This frustration may leave some incapable of focusing on their routine tasks with the usual efficiency. The person fasting is challenged by the temptation to eat something, even if it is only a small piece of candy, simply in order to eliminate the taxing hunger and resume a “normal life”. What the person does not commonly understand is that one of the main purposes of fasting is to disrupt the “normal life” and to introduce some aspects of a NEW LIFE.
Soon, there comes a critical moment in the fast, when the person finally learns to resist the thoughts of food, and to continually keep his mind engaged with other things. We might describe this state as a kind of somatic dissociation, supported by a displacement of the usual mental activities. In other words, this is when the power of the flesh is beginning to yield to the power of the will, instead of the other way around.
After this state has been achieved, whenever the craving for food strikes, it only serves to drive the person deeper into the other thoughts and activities which the person uses to displace the original ideas of enjoying food and the sensation of hunger. Of course, prayer is to be one of these main activities, and it is important that prayer is included, because once the mind is dislodged from its’ usual thought patterns, it becomes open to engage and embrace nearly any other exercise at hand. Other activities which may also be gainfully employed are BIBLE STUDY and FELLOWSHIP with other Christians. However, activities such as playing sports or other physically strenuous exercises may prove to be very punishing during a fast.
The Spiritual and Psychological Effects of Fasting
From my own experiences, I have learned that the most significant encounter with fasting is the DISCIPLINE of your habit, such that you are pressed to look beyond your human needs, and develop spiritual stamina and strength of will. Of course, the most obvious habits that are addressed through fasting, are your eating habits and your thinking habits, but the DISCIPLINE that is learned from this exercise can be applied to other facets of ones’ life.
Now that I have introduced the idea of how the mind is dissociated from its’ usual thought patterns during fasting, how the body is subjugated to the will, and how the mind becomes free to receive new training, the parables of the Patches and the Wineskins may now take on a significant meaning. The basic idea is that the old must be matched with the old, and the new must be matched to the new, and the old and the new cannot be superimposed without a catastrophe. If we presume that our physical habits and thought processes are the garments and wineskins, respectively, then we can conclude that these parables imply the following…
A new discipline in thought and behavior cannot coexist with the old frame of habits.
Moreover, a period of fasting is what separates the old and the new.
Physiological Effects of Fasting
According to Wikipedia, glucose is the body’s primary fuel source and is essential for the brain’s functioning. When denied glucose for more than 8 hours, the body will turn to the liver for glycogen, a storage form of glucose, to be used for fuel. The body will also use small amounts of protein to supplement this fuel. This fuel will last for up to 12 hours before the body needs to turn to muscle stores of glycogen, lasting for a few more days. If glucose is still denied at this point, muscle wasting is prevented by temporarily switching to fat as the fuel source, meaning fat is converted into ketone through catabolism. Ketones, while not sugars, are able to be used by the brain as a fuel source as long as glucose is denied.
The body will continue to use fat for as long as there is fat to consume. The body will generally indicate to the faster when fat levels are running extremely low (less than 7% and 10% of body weight for males and females, respectively) with an increased urge for food. Fasts are usually broken long before this point. If the fast is not broken, starvation will begin to occur, as the body begins to use protein for fuel.
According to this information, we can make a few conclusions as follows, towards answering the questions posed earlier.
What Should I Eat and What Should I Not Eat?
Fasting, from a physiological standpoint, is essentially depriving the body of the intake of glucose and/or similar forms of sugar. These sugars, including glucose, sucrose, fructose, maltose, etc. can be found in, or derived from foods like wheat, rice, corn or any other grain, bread, potatoes, crackers or any kind of carbohydrate, sweet fruits, sugar, honey, alcohol, nuts… Fat is also included, which is found in all meat, poultry and seafood, and is a very complex form of sugar. Apparently, the only foods that do not contain a source of glucose are non-starchy vegetables, such as broad-leaf greens.
Eating only vegetables is one kind of fast described in the Bible as the “Daniel Fast”. Daniel 1:5,8-16 indicates that Daniel refused to eat delicacies and wine from the King’s table, and only ate vegetables. The results were that “their features appeared better and fatter in flesh than all the young men who ate the portion of the king’s delicacies.”
It should be noted that the Daniel Fast is more extreme than vegetarianism, which, for most people, is merely the exclusion of animal products from the diet.
How Long Should I Fast?
A person needs to fast for at least 8 hours before any physiological changes take place, and for 20 hours before the body begins to rely on itself for energy. So this might gives us a clue about how long one should fast. From a physiological point of view, in my opinion, 30 to 40 hours is a good length of time to fast. This length of time is long enough to cause a change of chemistry and body processes, but falls short of a harsh destruction of the body.
For those of you who might expect to lose weight and get trim by not eating, it is evident that fasting cannot be expected to reduce the fat content of the body, unless it is extended longer than several days. This is obviously a very self-destructive way to lose weight, and I would not encourage anyone to fast simply to lose weight.
A Daniel fast may be extended longer, while still remaining safe in terms of health. I have known of more than one person who embarked on a “40-Day Daniel Fast”, and it was apparent that it helped them in many aspects of their physical and spiritual lives, even allowing them to overcome addictive types of behaviors and to make effective confessions, all leading to a greatly enhanced life in the Spirit.
My Anecdotal Experiences with Fasting
My first experience in fasting was when I was in graduate school. I fasted for weeks at a time, eating only one meal a day consisting of (1) sweetened rice porridge or oatmeal, (2) raw cucumbers or tomatoes, (3) pickled turnips or bamboo shoots, (4) tofu or salted eggs, and (5) water. Two or three times a week, I would eat a baked salmon steak with my meal, and treat myself to a Coca-Cola. On days when I needed an extra boost, I would eat a slice of toast with peanut butter for breakfast.
I was not very strong or healthy during that time, but I did become very sharp spiritually, and that helped me to draw much closer to God, and also to concentrate and finish my thesis requirements. Perhaps the most significant benefit I experienced from this fasting was a release from some habitual sins that had controlled me since adolescence.
Looking back however, in spite of these benefits, I think my fasting was too severe, because it affected my health so much that I had to quit studying for short periods of time due to illness. In fact, once during this time, I was bedridden for two months. The doctor said I had mononucleosis, which may have been obvious from a medical point of view, but in my heart, I believe my fatigue and weakened immune system was related to my extended fasting.
A few years later, and not too long ago, I fasted in a much different fashion. I abstained from eating any form of pork, and any kind of fried food, including potato chips, etc., which “sort of” conformed to the dietary requirements specified under the Mosaic Law. This was difficult for me, because I love to eat bacon, ham and all kinds of sausages, but after I got into the habit, I noticed that I felt much better in terms of health and conscience.
Biblical and Current Information About Fasting
The Bible has a lot to say about fasting. Scriptures relating to fasting include…
- Isaiah 58 – Fasting is a discipline that should be meant to please God.
- The Book of Daniel – Fasting is a source of good health and prosperity.
- Matthew 6:16-18 – Fasting should be done privately, seen only by God.
- Matthew 9:14-17; Mark 2:18-22; Luke 5:33-39 – Jesus is questioned about fasting.
- Matthew 17:14-21; Mark 9:14-29 – Fasting and prayer impart greater spiritual power.
- 1st Corinthians 7:5 – Fasting and prayer are the only reasons given for which people may forsake fellowship.
The Bible also contains countless examples of people who fasted for various causes.
In addition to the Bible, there is a lot more to be learned about fasting from Christian organizations and the medical profession. Lately, there is a lot more information that is readily available about fasting, than there was ten years ago. Anyone who is serious about performing a fast should first do a little research and get a very complete description of the nature and procedures for fasting, which are insightful and useful for going into the fast.
- Jen’s Ultimate Guide to Intermittent Fasting, including 15 amazing benefits of intermittent fasting.
- WebMD provides a cursory overview of Fasting from a medical perspective.
- Wikipedia also provides a broad overview of fasting which may be of interest to the casual reader.
Isaiah 58 is a lengthy passage with a focus on fasting, which is worthy to read at this point. It is apparent in verses 1-3 that the benefits of fasting are lost if one does not submit to the Lord’s discipline and a renewal of the mind. Verses 4-9a makes clear that the Lord intends to use a time of fasting to discipline His people, and to teach them a higher plane of thought. Verses 9b-14 are very important, as they describe many promises to the one who submits himself to the leading of the Lord.
1 “Cry aloud, spare not; Lift up your voice like a trumpet; Tell My people their transgression, And the house of Jacob their sins.
2 Yet they seek Me daily, And delight to know My ways, As a nation that did righteousness, And did not forsake the ordinance of their God. They ask of Me the ordinances of justice; They take delight in approaching God.
3 ‘Why have we fasted,’ they say, ‘and You have not seen? Why have we afflicted our souls, and You take no notice?’ “In fact, in the day of your fast you find pleasure, And exploit all your laborers.
4 Indeed you fast for strife and debate, And to strike with the fist of wickedness, You will not fast as you do this day, To make your voice heard on high.
5 Is it a fast that I have chosen, A day for a man to afflict his soul? Is it to bow down his head like a bulrush, And to spread out sackcloth and ashes? Would you call this a fast, And an acceptable day to the LORD?
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?
7 Is it not to share your bread with the hungry, And that you bring to your house the poor who are cast out; When you see the naked, that you cover him, And not hide yourself from your own flesh?
8 Then your light shall break forth like the morning, Your healing shall spring forth speedily, And your righteousness shall go before you; The glory of the LORD shall be your rear guard.
9 Then you shall call, and the LORD will answer; You shall cry, and He will say, ‘Here I am.’
“If you take away the yoke from your midst, The pointing of the finger, and speaking wickedness, 10 If you extend your soul to the hungry and satisfy the afflicted soul, Then your light shall dawn in the darkness, And your darkness shall be as the noonday.
11 The LORD will guide you continually, And satisfy your soul in drought, And strengthen your bones; You shall be like a watered garden, And like a spring of water, whose waters do not fail.
12 Those from among you shall build the old waste places; You shall raise up the foundations of many generations; And you shall be called the Repairer of the Breach, The Restorer of Streets to Dwell In.
13 “If you turn away your foot from the Sabbath, From doing your pleasure on My holy day, And call the Sabbath a delight, The holy day of the LORD honorable, And shall honor Him, not doing your own ways, Nor finding your own pleasure, Nor speaking your own words,
14 Then you shall delight yourself in the LORD; And I will cause you to ride on the high hills of the earth, And feed you with the heritage of Jacob your father. The mouth of the LORD has spoken.”
It is my prayer that you’ll find a blessed renewal of your mind and body through your fasting, and that you might come to realize all these promises of God in your life.
- Sigma Frame: Less Weight, Better Health! (January 3, 2013)
- Collective Evolution: Neuroscientist Shows What Fasting Does To Your Brain & Why Big Pharma Won’t Study It (December 11, 2015)