Good Friday, which is towards the end of the Lenten season, is traditionally an important day of communal fasting for adherents of the Reformed faith. In addition, within the Puritan/Congregational tradition of Reformed Christianity, special days of humiliation and thanksgiving "in response to dire agricultural and meteororological conditions, ecclesiastsical, military, political, and social crises" are set apart for communal fasting.
^ 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.
As an expression of lamentation and/or penitence, fasting nearly always is associated with weeping ( Judges 20:26 ; Esther 4:3 ; Psalm 69:10 ; Joel 2:12 ), confession ( 1 Sam 7:6 ; Dan 9:3 ), and the wearing of sackcloth ( 1 Kings 21:27 ; Neh 9:1 ; Esther 4:3 ; Psalm 69:10 ; Dan 9:3 ). In the New Testament Jesus chides the hypocritical Pharisees for disfiguring their faces when they fast ( Matt 6:16-18 ), a reference no doubt to the custom of smearing themselves with ashes. These objects and actions had no intrinsic penitential value but in a culture in which inner feelings were commonly displayed or even dramatized, when done sincerely they effectively communicated contrition. It became easy, however, for the outward exhibition of repentance to take the place of a genuine, inner attitude and thus become an act of hypocrisy.
^ Jacobs, Henry Eyster; Haas, John Augustus William (1899). The Lutheran Cyclopedia. Scribner. p. 110. By many Lutherans Good Friday is observed as a strict fast. The lessons on Ash Wednesday emphasize the proper idea of the fast. The Sundays in Lent receive their names from the first words of their Introits in the Latin service, Invocavit, Reminiscere, Oculi, Lcetare, Judica.
In 2012, Carolyn Corbin, who lives in the Channel Islands, got some firsthand experience with fasting’s flexibility. At 5 feet, 2 inches tall and 159 pounds, Corbin was overweight, with a BMI of 29.1. After seeing Mosley’s BBC show, she took up the 5:2 regimen, eating 500 calories two days a week and eating normally the rest of the time. She soon switched to water-only fasts two days a week. Since taking up the practice, the 65-year-old has lost 35 pounds and kept it off. “Forget calorie counting, diet food and diet drinks,” Corbin says. “Fasting for weight loss works.”
The bigu (辟谷 "avoiding grains") fasting practice originated as a Daoist technique for becoming a xian (仙 "transcendent; immortal"), and later became a Traditional Chinese medicine cure for the sanshi (三尸 "Three Corpses; the malevolent, life-shortening spirits that supposedly reside in the human body"). Chinese interpretations of avoiding gu "grains; cereals" have varied historically; meanings range from not eating particular foodstuffs such as food grain, Five Cereals (China), or staple food to not eating anything such as inedia, breatharianism, or aerophagia.
The biggest concern most people have is that Intermittent Fasting will lead to lower energy, focus, and the “holy crap I am hungry” feeling during the fasting period and ruin them. People are concerned that they will spend all morning being miserable because they haven’t consumed any food, and thus will be miserable at work and ineffective at whatever task it is they are working on.
Jimmy Kimmel lost 25 pounds on the 5:2 diet, eating fewer than 500 calories on Mondays and Thursdays then eating whatever he wants the rest of the week. Actor Benedict Cumberbatch also lost on the 5:2 diet while Hugh Jackman had a different intermittent fasting schedule. Each day he ate during an eight hour period but fasted for the remaining 16 hours. Is this just a Hollywood fad or are there real benefits to intermittent fasting?
Along with obligatory prayer, it is one of the greatest obligations of a Bahá'í. In the first half of the 20th century, Shoghi Effendi, explains: "It is essentially a period of meditation and prayer, of spiritual recuperation, during which the believer must strive to make the necessary readjustments in his inner life, and to refresh and reinvigorate the spiritual forces latent in his soul. Its significance and purpose are, therefore, fundamentally spiritual in character. Fasting is symbolic, and a reminder of abstinence from selfish and carnal desires."