An understanding of the physiological effects of fasting began to evolve in the latter part of the 19th century, when some of the first organized studies of fasting were carried out in animals and humans. In the 20th century, as more became known about nutrition and the nutritional requirements of the human body, methods of fasting became increasingly sophisticated, and a wide array of approaches emerged. For example, fasting was used as a treatment and as a form of disease prevention, and it was carried out in various settings (e.g., in a hospital or clinic or at home). Some fasting methods, particularly those applied in the treatment of chronic diseases, lasted more than a month, allowed for the consumption of only water or calorie-free tea, and included exercise and enemas. Other methods, generally referred to as modified fasting, allowed for the intake of 200 to 500 kilocalories per day (daily calorie needs of adults range from about 1,600 to 3,000 kilocalories, depending on sex, age, and activity level) and sometimes included psychological or spiritual therapy; depending on the particular method used, calories usually were in the form of bread, vegetable broth, fruit juice, honey, or milk. Modified fasting was distinguished from a very low-calorie diet, which allowed up to 800 kilocalories per day and typically was aimed at inducing substantial weight loss. Intermittent fasting involved cyclic periods of calorie restriction, such as a 24-hour period of fasting followed by a 24-hour period of regular calorie consumption.
Even with these results, one of the concerns with fasting is that people will binge on non-fast days. But the results of two months-long trials, published in 2018 in the journal Food Science & Nutrition, showed that dieters, specifically those following 5:2, didn’t binge. “When you impose a two-day 70 percent calorie restriction, what they do on the natural days is eat about 25 percent less,” says Harvie, one of the authors of the study and a co-developer of the 5:2 diet. “And that is why the diet is so effective.”
American King James Version×). Jesus knew that His true disciples, once He was no longer there in the flesh with them, at times would need to fast to regain and renew their zeal to serve Him (Mark 2:18-20 Mark 2:18-20 18 And the disciples of John and of the Pharisees used to fast: and they come and say to him, Why do the disciples of John and of the Pharisees fast, but your disciples fast not? 19 And Jesus said to them, Can the children of the bridal chamber fast, while the bridegroom is with them? as long as they have the bridegroom with them, they cannot fast. 20 But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days. 

Current research on intermittent fasting – the general term for diets like 5:2 – suggests that the approach is at least as effective as ‘normal’ dieting. Further research is investigating potential benefits in terms of blood sugar, and the ‘inflammatory response’ in the body that is a factor in many medical conditions, including cardiovascular disease, cancer and dementia.

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. [7,8]
If you keep fast, to count everyday pledge yourself you will act honest, sincere, controls your desires, mediate. This is a way how you make yourself free of five thieves: "On the ninth day(naomi) of the month, make a vow to speak the Truth, and your sexual desire, anger and desire shall be eaten up. On the tenth day, regulate your ten doors; on the eleventh day, know that the Lord is One. On the twelfth day, the five thieves are subdued, and then, O Nanak, the mind is pleased and appeased. Observe such a fast as this, O Pandit, O religious scholar; of what use are all the other teachings? ||2||" (Guru Granth Sahib Ji, Ang 1245)
Many physiological changes occur in the body during fasting. During the first day or so, the body uses its glycogen reserves, the sugars that are the basic energy supply. After these are depleted, the body begins using fat. However, the brain, which has high fuel requirements, still needs glucose (sugars converted from glycogen). To obtain glucose for the brain, the body begins to break down muscle tissue during the second day of the fast. Thus, during fasting some muscle loss will occur. To fuel the brain, the body would need to burn over a pound of muscle a day, but the body has developed another way to create energy that saves important muscle mass. This protein-sparing process is called ketosis, which occurs during the third day of a fast for men and the second day for women. In this highly efficient state, the liver begins converting stored fat and other nonessential tissues into ketones, which can be used by the brain, muscles, and heart as energy. It is at this point in the fast that sensations of hunger generally go away, and many people experience normal or even increased energy levels. Hormone levels and certain functions become more stable in this state as well. The goal of most fasts is to allow the body to reach the ketosis state in order to burn excess fat and unneeded or damaged tissue. Thus, fasts longer than three days are generally recommended as therapy.
When I was forty-two years old, I went to an Assemblies of God camp in Alexandria,Minnesota, to speak for a women's retreat. The first two days of the retreat went very well, and then I had one day in between the first retreat and the second -- so many women had registered, the camp could not host all of the women at the same time. I took that day in this lovely place in Minnesota to enjoy the lakes and trees -- it was a gorgeous environment -- and to fast and pray about God's will for my life. I felt as if I was doing a lot of good things, but I also thought I might miss God's best for me. I longed to hear from God and to receive a revelation from Him about my life.
American King James Version×), though other national fast days are mentioned in the Bible. Also, personal fasts are clearly expected of Christ’s disciples (Matthew 9:14-15 Matthew 9:14-15 14 Then came to him the disciples of John, saying, Why do we and the Pharisees fast oft, but your disciples fast not? 15 And Jesus said to them, Can the children of the bridal chamber mourn, as long as the bridegroom is with them? but the days will come, when the bridegroom shall be taken from them, and then shall they fast.
Fasting is a practice in several Christian denominations and is done both collectively during certain seasons of the liturgical calendar, or individually as a believer feels led by the Holy Spirit.[35] In Western Christianity, the Lenten fast is observed by many communicants of the Catholic Church, Lutheran Churches, Methodist Churches, Reformed Churches, Anglican Communion, and the Western Orthodox Churches and is a forty-day partial fast to commemorate the fast observed by Christ during his temptation in the desert.[36][37] While some Western Christians observe the Lenten fast in its entirety, Ash Wednesday and Good Friday are nowadays emphasized by Western Christian denominations as the normative days of fasting within the Lenten season.[38][39]

One potential disadvantage of this schedule is that because you typically cut out a meal or two out of your day, it becomes more difficult to get the same number of calories in during the week. Put simply, it's tough to teach yourself to eat bigger meals on a consistent basis. The result is that many people who try this style of intermittent fasting end up losing weight. That can be a good thing or a bad thing, depending on your goals.
The Fast Diet is only an eating pattern, but that doesn't mean you shouldn't exercise. In fact, being physically active lowers your risk of heart disease and diabetes, helps keep weight off and increases your energy level. Most experts suggest getting at least 30 minutes of moderate-intensity exercise – like brisk walking – most or all days of the week.
Another type of intermittent fasting, alternate day fasting has you severely restricting the amount of calories you eat during fasting days, then eating to your stomach’s content on non-fasting days. Food isn’t completely off the table, but you’ll stick to about 25 percent of your normal caloric intake. Someone eating 2,000 calories would cut back to 500, for example. Alternate-day fasting isn’t necessarily a long-term plan, because it can become difficult to stick to, but it can be helpful to get a healthy habit in motion.

Fasting is obligatory for every Muslim one month in the year, during Ramadhan. Each day, the fast begins at sun-rise and ends at sunset. During this time Muslims are asked to remember those who are less fortunate than themselves as well as bringing them closer to God. This also helps to give the digestive system a break. Non obligatory fasts are two days a week as well as the middle of the month, as recommended by the Prophet Muhammad.


Save high-intensity interval training and heavy weight training for feed days/during your feed window, if you can, when you have the calories for fuel and nutrients for recovery. But if your training schedule calls for a grueling workout on a fast day that can’t be moved, add the calories burned to your count for the day so you don’t burn through muscle. At 200 or 300 calories, you don’t need to compensate, but if you burn 500 or more on a fast day, instead of just 500 maintenance calories with 50g of protein, eat 1,000 calories with 80g or more of protein, Varady advises.
How It Works: Fast for 24 hours once or twice per week. During the 24 hour fast, which creator Brad Pilon prefers to call a “24 break from eating,” no food is consumed, but you can drink calorie-free beverages. After the fast is over, you then go back to eating normally. “Act like you didn’t fast,” Pilon says. “Some people need to finish the fast at a normal mealtime with a big meal, while others are OK ending the fast with an afternoon snack. Time it however works best for you, and adjust your timing as your schedule changes,” he says.
Those fasting may experience side effects of fatigue, malaise, aches and pains, emotional duress, acne, headaches, allergies, swelling, vomiting, bad breath, and symptoms of colds and flu. These reactions are sometimes called healing crises, which are caused by temporarily increased levels of toxins in the body due to elimination and cleansing. Lower energy levels should be expected during a fast.
The Bible also gives instructions about the attitude and approach we should have in fasting. Jesus warned about hypocritical fasting, trying to show off or make others feel sorry for us.In the New Testament, Anna, the prophetess, is described as serving God day and night with fasting and prayers (Luke 2:37). We read that John the Baptist taught his disciples to fast and Jesus Christ said His disciples would fast after His death (Mark 2:18-20). Paul and Barnabas prayed and fasted when they ordained elders in the Church (Acts 14:23). And Jesus Christ fasted 40 days and nights before facing Satan in an epic battle of spiritual will (Matthew 4:2).
That said, I have heard that women may find a wider window of eating to be more favorable when doing daily intermittent fasting. While men will typically fast for 16 hours and then eat for 8 hours, women may find better results by eating for 10 hours and fasting for 14 hours. The best advice I can give anyone, not just women, is to experiment and see what works best for you. Your body will give you signals. Follow what your body responds favorably to.
Secular Music Fast: Instead of listening to Top Hits on the radio, you can choose to listen to the Christian radio station for a period of time. Pop in a CD of your favorite worship leader when you're driving to work. Listen to a Christian podcast or audiobook. You can even turn the stereo off completely and spend that time in prayer. You'll be amazed what this little change will do for your life. 
When your empty stomach starts to growl and begins sending your brain every “feed me” signal it can, don’t be content to let your mind dwell on the fact that you haven’t eaten. If you make it through with an iron will that says no to your stomach, but doesn’t turn your mind’s eye elsewhere, it says more about your love for food than your love for God.
Hi Adrian. I hope all is well with you. I was referred to subscribe to your channel last night and I did. Well, not sure where to start BUT... I have been on my journey with weight loss for a while now and on April 16th of this year I decided to try intermittent fasting. I broke my fast a few times the first week but after that I have been doing well, going to the gym and working out 4-5 days a week doing mostly cardio. From what I've been reading and seeing about IF, people are losing 5-8 lbs a week. Me? I've only lost 4.7 lbs. I am happy for the 4.7lbs down but I was thinking that being the weight that I started (245.4 lbs) would mean I would lose the weight faster. No? I also am watching what I eat via MyFitnessPal to help me count my calories. I usually east between 1200 - 1450 calories. There are days that I have eaten a little less but not much. Also I am 5'1. Please help me because I am discouraged and frustrated doing all I think is right with IF but not seeing the maximum results as people have mentioned. What do you think may be the issue here? Also there is nothing wrong with me medically to say that's the reason I am not losing much weight. I hope to hear from you because I really don't want to give up. I am trying to be healthy! Thank you. (I also sent this message to you on YouTube. Not sure which messages you check more frequently).

Biblical fasting is a spiritual discipline which was encouraged by Jesus, Himself, while He was on earth. When questioned as to why the Pharisees and the disciples of John the Baptist fasted while Jesus disciples did not, Jesus answered, "How can the guests of the bridegroom mourn while he is with them? The time will come when the bridegroom will be taken from them; then they will fast” (Matthew 9:15).

But while these diets have gained popularity, there have been only a few longitudinal studies on whether they actually lead to sustained weight loss. (U.S. News & World Report has a breakdown of past research into fasting diets.) Now there’s a new credible study to add to the mix: This 50-week study of 150 obese and overweight adults published in The American Journal Of Clinical Nutrition found that the 5:2 fasting diet was “equivalent but not superior to” conventional dieting in terms of weight loss and the prevention of metabolic diseases.

Intermittent fasting also has a number of added benefits over strict calorie restriction. For starters, it's a lot easier to comply with, and compliance is everything. The calorie restriction route is also extremely dependent on high quality nutrition — you want to sacrifice calories without sacrificing any important micronutrients — and this can be another hurdle for many who are unfamiliar with nutrition and what actually constitutes a healthy diet.
Biblical fasting brings us into a closer union with God. While our bodies are being deprived for the purpose of drawing near to God, He has promised in return to draw near to us. This is a spiritual certainty. As we decrease, the Spirit increases. As individuals we are strengthened and renewed. “...Though outwardly we are wasting away, yet inwardly we are being renewed day by day” (2 Corinthians 4:16).
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:

You'll probably lose weight on the Fast Diet because you’ll consume significantly fewer calories than you normally would on two days of the week. If you actually stick with the plan, you'll steadily drop weight. And because the two fast days are nonconsecutive and allow for at least some eating, the diet authors have found that people don't typically binge and overeat on the nonfasting days.
To restore balance or to lose weight, we simply need to increase the amount of time we burn food energy. That’s intermittent fasting. In essence, fasting allows the body to use its stored energy. After all, that’s what it is there for. The important thing to understand is that there is nothing wrong with that. That is how our bodies are designed. That’s what dogs, cat, lions and bears do. That’s what humans do.
That breakthrough might be in the realm of the spirit. It may be in the realm of your emotions or personal habits. It may be in the realm of a very practical area of life, such as a relationship or finances. What I have seen repeatedly through the years-not only in the Scriptures but in countless personal stories that others have told me -- is that periods of fasting and prayer produce great spiritual results, many of which fall into the realm of a breakthrough. What wasn't a reality . . . suddenly was. What hadn't worked . . . suddenly did. The unwanted situation or object that was there . . . suddenly wasn't there. The relationship that was unloving . . . suddenly was loving. The job that hadn't materialized . . . suddenly did.
Thirty-six young healthy male volunteers were placed on a 24-week calorie-restricted diet of about 1,600 calories per day. They also had to walk for about 45 minutes a day. But instead of resulting in continuous weight loss, at 24 weeks their weight had stabilized, and no more weight loss could be elicited even when he reduced calorie intake down to 1,000 or less per day.
Fasting in the Ethiopian Church implies abstention from food and drink. No animal products are consumed, including dairy, eggs and meat, and utensils that have touched such products must be washed before touching the strictly vegan foods that are consumed on fast days. During fast periods, Holy Liturgy (Mass) is held at noon (except on Saturdays and Sundays), and because no food can be consumed before communion, it is traditional for people to abstain from food until mass is over (around 2 to 3 in the afternoon). Every Wednesday and Friday are days of fasting because Wednesday is the day that the Lord was condemned and Friday is the day he was crucified (the Wednesdays and Fridays between Easter Sunday and Pentecost Sunday are an exception as well as when Christmas or Epiphany fall on a Wednesday or a Friday). The fasts that are ordained in the canon of the Church of Ethiopia are:
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