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".
1) A soul cleansing. How often we forget that our bodies are the temple of the Lord—especially when deciding what to eat! Fasting is a great time to remember the spiritual connection we have to our physical bodies. Without the toxins we put in our bodies, we not only give our bodies a break from the digestive process, but we also allow our spirits to be detoxed. Fasting is a faith-move, an expectation we have that God will fill us with His Holy Spirit, just as He promised. But as Christ told His disciples, “[N]o one pours new wine into old wineskins. Otherwise, the wine will burst the skins, and both the wine and the wineskins will be ruined. No, they pour new wine into new wineskins." By fasting, we meditate cleanses the soul and makes it new so we can receive the Holy Spirit and become empowered to live for Christ in a new way.
Never forget that the fruit of the tree of the knowledge of good and evil was the knowledge of good and evil. There was an element of good in that fruit, not just evil. The devil told Eve specifically that the fruit of the tree was "good for food, and that it was pleasant to the eyes" (Gen. 3:6). All Eve had to do was look to see that the fruit was pleasant. She made a bad assumption, however, that what was visually pleasant would also be "good for food." In that, the devil was very wrong!
For this plan, eat clean for five days of the week (you can pick whatever days you want). On the other two days, restrict your calories to no more than 700 each day. Calorie restriction unlocks a lot of the same benefits as fasting for an entire day. On your non-fasting days, you’ll need to make sure you're getting in healthy fats, clean meats, vegetables, and some fruits, and you can structure your meals however best works for you. On restricted days you can have smaller meals or snacks throughout the day or have a moderate-size lunch and dinner and fast in the morning and after dinner. Again, focus on healthy fats, clean meats, and produce. An app like MyFitnessPal can help you log your food and keep track of your calorie intake so you don’t go over 700.
As you pray and fast, you will call on God, and He will answer you. Answered prayer is the quintessence of praying and fasting. If I were to share with you the five or six pages of the prayer journal I prepared prior to my first forty-day fast, and then walk you back through my journal since then, you would see one thing: My prayers were answered. They are still being answered. There is something to the disciplines of prayer and fasting. I could point you to every experience of long-term fasting where God has answered my requests before Him. This does not mean they were answered as I preferred, but it did not matter. He had worked in my heart, and I was released, fully confident that God was ordering my way. When we humble ourselves before the Father, and when God sees we are serious about giving Him our broken spirits, He begins to do things we have never seen before. It’s empowering. It sensitizes us to the needs of others at home and overseas as we suddenly find ourselves quietly praying for people, events, and situations with the knowledge that our prayers not only will be heard but that the Father will answer them.
In terms of your comment regarding water yes millions of people may do this and as you say it has little impact and harm. I however prefer to drink water on a regular basis; it is what the body is primarily made up of and what the cells need for repair and regeneration. That and because many of us often think we are hungry when in fact we are dehydrated and the body is wanting more water – wanting more fluids this is why I encourage people to drink more water during fasting days than do a total fast.
Before you start your IF plan, it's important to talk with a professional to make sure it's right for you. Women should be especially cautious as there are some mixed opinions on whether or not certain fasting protocols are healthy for female hormone balance. In addition, if you have adrenal fatigue or gut health issues you'll want to proceed with caution. If you have a history of disordered eating, you'll probably want to avoid fasting altogether..
Cons: Even though there is flexibility in when you eat, Leangains has pretty specific guidelines for what to eat, especially in relation to when you’re working out. The strict nutrition plan and scheduling meals perfectly around workouts can make the program a bit tougher to adhere to. (You can learn more about the specifics — as well as when to time these meals — directly from Leangains here and here.)
Whole-day fasting involves regular one-day fasts. The strictest form would be alternate day fasting (ADF). This involves a 24-hour fast followed by a 24-hour non-fasting period. The alternate day modified fasting (ADMF) and 5:2 diets—the latter defined as five days per week not fasting and two days per week either total fasting or modified fasting—both allow the consumption of approximately 500–600 calories on fasting days.
As it turns out, the science behind these diets is still pretty nascent and exploratory — more than the acolytes might have you believe. While there’s lots of animal research, human studies on fasting are only just beginning to ramp up. And while we have learned that fasting helps people lose weight, it’s only if you can stick with it. But that doesn’t make fasting any less fascinating. Here’s what we know and don’t know.
Fasting isn’t merely an act of self-deprivation, but a spiritual discipline for seeking more of God’s fullness. Which means we should have a plan for what positive pursuit to undertake in the time it normally takes to eat. We spend a good portion of our day with food in front of us. One significant part of fasting is the time it creates for prayer and meditation on God’s word or some act of love for others.
Wesley Duewel, a twentieth-century writer, said, “You and I have no more right to omit fasting because we feel no special emotional prompting than we have a right to omit prayer, Bible reading, or assembling with God’s children for lack of some special emotional prompting. Fasting is just as biblical and normal a part of a spiritual walk of obedience with God as are these others.”
One reason experts tell people not to cut way back on calories is that it can slow your metabolism, making it even harder to lose weight. But studies show that fasting from time to time can be an effective strategy for weight loss. In addition, cutting calories on a couple of days instead of every day may help preserve muscle, so you lose mostly fat.
A 2018 review of intermittent fasting in obese people showed that reducing calorie intake one to six days per week over at least 12 weeks was effective for reducing body weight on an average of 7 kilograms (15 lb); the results were not different from a simple calorie restricted diet, and the clinical trials reviewed were run mostly on middle-aged women from the US and the UK, limiting interpretation of the results. Intermittent fasting has not been studied in children, the elderly, or underweight people, and could be harmful in these populations.
Once or twice per week you can have a treat. Remember you will have 600-1000 calories to work with in the main meal. This should make it pretty easy to enjoy some of your favorite foods or go out to a restaurant with friends/family. Just make sure to not go over the calorie budget for the day. If you do end up going over the calorie budget for the day then you can compensate by slightly reducing calories the following days.
In addition to the fasts mentioned above, Roman Catholics must also observe the Eucharistic Fast, which involves taking nothing but water and medicines into the body for one hour before receiving the Eucharist. The ancient practice was to fast from midnight until Mass that day, but as Masses after noon and in the evening became common, this was soon modified to fasting for three hours. Current law requires merely one hour of eucharistic fast, although some Roman Catholics still abide by the older rules.