What is ghrelin? It is actually also known as the hunger hormone, because it is responsible for telling your body that it is hungry. Dieting and really restrictive eating can actually increase ghrelin production, which will leave you feeling hungrier. But when you fast, though you might struggle in the first few days, you’re actually normalizing ghrelin levels.
In Methodism, fasting is considered one of the Works of Piety. The Discipline of the Wesleyan Methodist Church required Methodists to fast on "the first Friday after New-Year's-day; after Lady-day; after Midsummer-day; and after Michaelmas-day." Historically, Methodist clergy are required to fast on Wednesdays, in remembrance of the betrayal of Christ, and on Fridays, in remembrance of His crucifixion and death. "The General Rules of the Methodist Church," written by the founder of Methodism, John Wesley, wrote that "It is expected of all who desire to continue in these societies that they should continue to evidence their desire of salvation, by attending upon all the ordinances of God, such are: the public worship of God; the ministry of the Word, either read or expounded; the Supper of the Lord; family and private prayer; searching the Scriptures; and fasting or abstinence." The Directions Given to Band Societies (25 December 1744) mandated fasting and abstinence from meat on all Fridays of the year, a practice that was reemphasized by Phoebe Palmer and became standard in the Methodist churches of the holiness movement. Wesley himself also fasted before receiving Holy Communion "for the purpose of focusing his attention on God," and asked other Methodist Christians to do the same. In accordance with Scripture and the teachings of the Church Fathers, fasting in Methodism is done "from morning until evening"; John Wesley kept a more rigorous Friday Fast, fasting from sundown (on Thursday) until sundown (on Friday) in accordance with the liturgical definition of a day. The historic Methodist homilies regarding the Sermon on the Mount also stressed the importance of the Lenten fast. The United Methodist Church therefore states that:
Fasting is not the first dietary approach to excite researchers. Before fasting, there was caloric restriction, or CR. The methods have much in common. Overall, they both drastically reduce energy intake and bring about similar health benefits. They’re like siblings in a way, especially since fasting studies emerged from work on CR. And now, many former CR researchers are exploring fasting, often setting the two against each other in the lab.
Dietrich Bonhoeffer, in his book The Cost of Discipleship, said, “Jesus takes it for granted that His disciples will observe the pious custom of fasting. Strict exercise of self-control is an essential feature of the Christian life. Such customs have only one purpose — to make the disciples more ready and cheerful to accomplish those things which God would have done.”
In a physiological context, fasting may refer to the metabolic status of a person who has not eaten overnight, or to the metabolic state achieved after complete digestion and absorption of a meal. Several metabolic adjustments occur during fasting. Some diagnostic tests are used to determine a fasting state. For example, a person is assumed to be fasting once 8–12 hours have elapsed since the last meal. Metabolic changes of the fasting state begin after absorption of a meal (typically 3–5 hours after eating).