^ Pfatteicher, Philip H. (1990). Commentary on the Lutheran Book of Worship: Lutheran Liturgy in Its Ecumenical Context. Augsburg Fortress Publishers. pp. 223–244, 260. ISBN 9780800603922. The Good Friday fast became the principal fast in the calendar, and even after the Reformation in Germany many Lutherans who observed no other fast scrupulously kept Good Friday with strict fasting.
Understanding the potential adverse effects of intermittent fasting is limited by an inadequate number of rigorous clinical trials. One 2015 review of low-quality clinical studies found that short-term intermittent fasting may produce minor adverse effects, such as continuous feelings of weakness and hunger, headaches, fainting, or dehydration. Long-term fasting may cause eating disorders or malnutrition, with increased susceptibility to infectious diseases.
Intermittent fasting is hard in the contemplation, of that there is no doubt. “You go without food for 24 hours?” people would ask, incredulously when we explained what we were doing. “I could never do that.” But once started, it’s a snap. No worries about what and where to eat for one or two out of the three meals per day. It’s a great liberation. Your food expenditures plummet. And you’re not particularly hungry. … Although it’s tough to overcome the idea of going without food, once you begin the regimen, nothing could be easier.”
Having issues with an eating disorder, I feel equipped to answer your question. The purpose of fasting is to take the focus off of being fulfilled by anything other than God. You can confess your addiction to the Lord and fast with the anticipation that He will free you from this addiction. Fasting and praying can help you gain mastery over your thoughts and behaviors. The enemy will try to attack you with all kinds of nonsense, but if you are prepared for the attack with God's Word, you will stand strong. After breaking the fast, employ the wisdom and self control that you gained during the fast and refuse to accept your former behaviors.
Fasts may last for varying lengths of time -- one day, three days, seven days, and more. We should prayerfully seek the Lord about the length of our fast. Fasting should have an object in mind; we should have a clear idea of the need and purpose. One of the most pressing reasons for Christian fasting may be revival -- “Will you not revive us again...” (Psalm 85:6).
Fast from Going Out: Take a look at your calendar and pick a night when you'd usually go out and spend the time instead diving into Scripture. Maybe there's a book of the Bible you've always wanted to read but didn't have time. Perhaps you want to pray through the Psalms. Is there a person in the Bible you'd like to know more about? Give this time to God and let Him show you the great treasures of His Word!
Second, fasting seems foreign to many of us simply because nobody talks about it that much. The reason for this is that nobody stands to make much money by telling you to not eat their products, not take their supplements, or not buy their goods. In other words, fasting isn't a very marketable topic and so you're not exposed to advertising and marketing on it very often. The result is that it seems somewhat extreme or strange, even though its really not.
Thanks for bringing this to our attention, I believe Muslims are urged to fast entirely, whereas the fasting diet plan or 5:2 diet allows people to eat and drink a small amount of food throughout the day. Having said this if this is something you have been doing your entire life perhaps you have some great tips you can share that makes fasting easier?
I know many of you are itching to get started right away, but IF is not for everyone. It is not recommended for pregnant women, women who are breastfeeding, people with diabetes, or other people who need to closely regulate their blood sugar. In addition, there has not been research on participants who are underweight, very old, or very young (<18 yrs. old) and these populations could be at higher risk for experiencing negative consequences of fasting (Longo and Mattson , 2014). So please:
Many healers claim that fasting is a particularly useful therapy for Americans and for the modern lifestyle, subjected to heavy diets, overeating, and constant exposure to food additives and chemicals. Some alternative practitioners have gone so far as to estimate that the average American is carrying 5-10 pounds of toxic substances in their bodies, for which fasting is the quickest and most effective means of removal.
In addition to our attitudes towards God and our stance before man, our motives must also be correct. We should fast in order to further the building up of God’s kingdom by seeking to minister to others. The prophet Isaiah received from the Lord the acceptable motives for our fasts: “Is not this the kind of fasting I have chosen: to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke? Is it not to share your food with the hungry and to provide the poor wanderer with shelter -- when you see the naked, to clothe him, and not to turn away from your own flesh and blood?” (Isaiah 58:6-7).
AN IMPORTANT CAVEAT: Intermittent Fasting can be more complex for people who have issues with blood sugar regulation, suffer from hypoglycemia, have diabetes, etc. If you fit into this category, check with your doctor or dietitian before adjusting your eating schedule. It also affects women differently (there’s a whole section dedicated to that below)
Intermittent fasting (specifically the 5:2 diet) became popular in the UK in 2012 after the BBC2 television Horizon documentary Eat, Fast and Live Longer. Via sales of best-selling books, it became widely practiced. In the United States, intermittent fasting has become a trend among Silicon Valley companies. According to NHS Choices as of 2012, people considering the 5:2 diet should first consult a physician, as fasting can sometimes be unsafe. A news item in the Canadian Medical Association Journal expressed concern that promotional material for the diet showed people eating high-calorie food, such as hamburgers and chips, and that this could encourage binge eating since the implication was that "if you fast two days a week, you can devour as much junk as your gullet can swallow during the remaining five days".
DU: There are different kinds of fasting. Scientifically speaking, ‘fasting’ can be caloric restriction, intermittent fasting, or dietary restriction. Caloric restriction is simply cutting down your energy intake by 20 to 40 percent. Intermittent fasting involves forgoing food completely for a period of time, say morning till evening, and then eating normal meals the next day or so. Dietary restriction is limiting or eliminating a particular macronutrient from one’s meal, say proteins or carbohydrates, for a season.
How It Works: Warriors-in-training can expect to fast for about 20 hours every day and eat one large meal every night. What you eat and when you eat it within that large meal is also key to this method. The philosophy here is based on feeding the body the nutrients it needs in sync with circadian rhythms and that our species are “nocturnal eaters, inherently programmed for night eating.”
Getting back to intermittent fasting, many studies have confirmed the health benefits of calorie restriction, and it seems clear that eating less is part of the equation if you want to live longer. Interestingly, research4 has shown that life-long calorie restriction in mice "significantly changes the overall structure of the gut microbiota" in ways that promote longevity. So one reason why calorie restriction may lengthen lifespan appears to be due to the positive effect it has on gut microbiota.
I still don’t understand how many days in a row you have to do a fast. I guess if you are on a keto diet is is as many as you can do right. Iam new and have done 3 already. I have had some uncomfortalble side effects. but I found out it was due to lost of electrolights and I used chicken broth and more salt to make that go away. How many green veggies should I be eating in the 8 hour window? It all seems very confusing. I know lots of fat and no low fat cause of sugar.
Often when we slip up on a fast, we can let ourselves feel condemned and defeated. Breaking your fast in NOT a sin. If anything, you’ve proven your humanity, and 2 Corinthians 12:9 states that, “My strength is made perfect in weakness” (NKJV). God’s strength often shows up in our weakest moments. Don’t let a momentary lapse define your fast. We’re not pushing towards our stomach, we’re not even pushing to ourselves, but we are pushing to be closer to God.
These types of side effects weren’t more common in CR dieters overall, but several people had to pull out of the study because of safety concerns. Noted side effects of CR are chronic loss of bone density and lean body mass, and excessive weight loss. Some CR dieters have body mass indexes in the teens, which suggest malnutrition and frailty, Longo says.
In section 109, of the same book, Yudhishthira asks Bheesma "what is the highest, most beneficial" and fruitful "of all kinds of fasts in the world". Bheeshma says "fasting on the 12th day of the lunar month" and worship Krishna, for the whole year. Krishna is worshipped in twelve forms as Kesava, Narayana, Madhava, Govinda, Vishnu, the slayer of Madhu, who covered the universe in three steps, the dwarf (who beguiled Mahabali), Sridhara, Hrishikesha, Padmanabha, Damodara, Pundhariksha. and Upendra. After fasting, one must feed a number of brahmans. Bheeshma says " the illustrious Vishnu, that ancient being, has himself said that there is no fast that possesses merit superior to what attach to fast of this kind." 
Fasting is the willing abstinence or reduction from some or all food, drink, or both, for a period of time. An absolute fast or dry fasting is normally defined as abstinence from all food and liquid for a defined period. Water fasting refers to abstinence from all food and drink except water, but black coffee and tea may be consumed. Other fasts may be partially restrictive, limiting only particular foods or substances, or be intermittent.