It may sound really hard at first, but at least eight hours of the 16 is spent sleeping. There's also a lot of downtime between dinner and sleeping that adds up. Just be patient with yourself, and you'll find your body adjusting to this new eating schedule in no time. If you're looking to get started now, what better way than planning what you're going to eat during your eight-hour eating window?
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.)
The combination of fasting and praying is not a fad or a novelty approach to spiritual discipline. Fasting and praying are not part of a human-engineered method or plan. They are not the means to manipulate a situation or to create a circumstance. 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.
While this verse applies to our eternal destiny, the principle applies to our daily sojourn; as we humble and deprive our bodies through fasting, our spiritual man is made stronger and our senses more acute. This principle served the apostles well during the early church days. Their decisions were made through fasting and prayer; God gave them instructions and directions. “While they were worshiping the Lord and fasting, the Holy Spirit said, ‘Set apart for me Barnabas and Saul for the work to which I have called them.’ So after they had fasted and prayed, they placed their hands on them and sent them off” (Acts 13:2-3).
This mirrored some of what researchers were finding in non-human primates. Rhesus monkeys share 93 percent of their genetic makeup with humans and usually live to about 26 in captivity. In one study on 76 rhesus monkeys that’s been running since 1989 at the Wisconsin National Primate Research Center, monkeys on a 30 percent calorie cut lived, on average, two to three years longer than control monkeys. Another ongoing study, started in 1987 by the National Institute on Aging on 121 rhesus monkeys, hasn’t detected the same boost to longevity. But CR has worked remarkably well for the 10 males that started the diet later in life. At least four have lived past age 40, including one to 43 — a record for the species.
"How long you fast is entirely up to you and the leadership of the Holy Spirit. The Bible gives examples of fasts that lasted one day or part of a day (Judges 20:26; 1 Samuel 7:6; 2 Samuel 1:12; 3:35; Nehemiah 9:1; Jeremiah 36:6), a one-night fast (Daniel 6:18–24), three-day fasts (Esther 4:16; Acts 9:9), seven-day fasts (1 Samuel 31:13; 2 Samuel 12:16–23), a fourteen-day fast (Acts 27:33–34), a twenty-one day fast (Daniel 10:3–13), forty-day fasts (Deuteronomy 9:9; 1 Kings 19:8; Matthew 4:2), and fasts of unspecified lengths (Matthew 9:14; Luke 2:37; Acts 13:2; 14:23)." -What Christians Need to Know about Fasting by Sam Storms
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.
Fasting calls us to turn away from food. Fasting calls us to redivert our attention back to the things of God and His commandments. Fasting calls us to face and overcome the devil's call: "Has God really said you can't have this?" Fasting calls us to abstain from all things harmful for us, and in most cases, from all food for a period of time. The devil's insistent question is likely to become very loud in our minds as we begin a fast: "Has God really said you can't eat? Not anything? Not the things you love the most? Has God really called you to fast- to abstain totally from this thing that you have labeled as 'good'?"
Studies on every-other-day fasting show mixed results. One published in 2010 in the Nutrition Journal suggested that the technique was effective among a group of obese patients. A group of 16 participants ate only one meal – lunch – every other day, and they were limited to about 500 calories. That's the same amount of calories women consume on the Fast Diet's fasting days. On the days when the study participants were not fasting, they were not constrained to any rules. Over the course of eight weeks, the participants lost an average of 12 3/10 pounds.
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.
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.
In a 2011 study published by the American Association for Cancer Research, researchers at Genesis Prevention Center at University Hospital in South Manchester, England tested the effects of three kinds of diets on 115 women. One diet looked like the Fast Diet (five days of normal eating and two days following a calorie-restricted, low-carb diet each week), another restricted carbs two days a week but had no calorie restrictions and a final group followed a calorie-restricted Mediterranean diet for all seven days of the week. After four months, participants following the intermittent low-carbohydrate diets lost an average of 9 pounds, while those on the Mediterranean diet lost an average of 5 pounds.
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).