Fasting consists of voluntarily going without food for a period of time in order to sharpen the spiritual senses or prepare for religious ritual.

Abstaining from food, usually for religious or ethical reasons. In ancient religions it was used to prepare worshipers or priests to approach deities, to pursue a vision, to demonstrate penance for sins, or to assuage an angered deity. All the major world religions include fasting among their practices. Judaism has several fast days, notably Yom Kippur. For Christians Lent is set aside as a 40-day period of penitence before Easter, including the traditional fast days of Ash Wednesday and Good Friday. In Islam the month of Ramadan is observed as a period of total abstention from food from dawn to dusk. Fasting to make a political protest is often referred to as a hunger strike; hunger strikes have been employed by, among others, 19th-century female suffragists, Mohandas K. Gandhi, and late-20th-century Irish nationalists. Moderate fasting is also sometimes practiced for its claimed health benefits.
Religious fasting usually involves going without food at certain times (e.g. between sunrise and sunset).
In fasting, individuals or whole communities abstain from food and drink, usually for a specific reason and a specific amount of time. Fasting differs from dieting or avoidance of certain foods, in that it implies complete abstinence from food, with only small modifications such as time limits or subsistence liquids.
Judaism also calls for regular fasting as a part of its doctrine. The major fast, Yom Kippur (Fast of Atonement), the holiest Jewish holiday, falls on the tenth day of the Hebrew month of Tishri. The Old Testament specifies at least six other minor fasts. During all of these except Yom Kippur, which demands abstinence from sunset to sunset, faithful Jews fast from sunrise until the first night stars.
Most sects within Christianity have also advocated periods of fasting. The early Church called for voluntary fasts, but by the fourth century specific fasting practices were enumerated. In the past, the Roman Catholic Church required numerous fasts, including all Sundays during Lent, Easter week, and all Fridays except from Christmas to Epiphany and from Easter to Ascension. Today, the Church recommends only a few fasts. Adults (those over 21) and youths (those over 14) are expected to conduct limited fasts on Ash Wednesday and Good Friday, as well as a one hour fast before communion. The Greek Orthodox Church lists over 250 fast days, including the 40 days before Christmas and Easter. The Eastern Orthodox Church proscribes meat during the first week of Lent and then precludes other foods, including fish, cheese, oil, butter, and milk, for the duration.
In all faiths, religious ascetics, especially saints and holy figures, have undertaken extreme fasts as a path to spiritual perfection. Hindu Yogis, Greek priests, and Christian martyrs all fasted. Recently, historians have taken great interest in the fasting practices of medieval wome
Islam

In Islam, fasting for a month is an obligatory practice during the holy month of Ramadan, from fajr (dawn), until the maghrib (dusk). Muslims are prohibited from eating, drinking (including water), and engaging in sexual activity. They are also encouraged to temper negative emotions such as anger and addiction. Fasting in the month of Ramadan is one of the Pillars of Islam, and thus one of the most important acts of Islamic worship. By fasting, whether during Ramadan or other times, a Muslim draws closer to God by abandoning body pleasures, such as food and drink. This makes the sincerity of their faith and their devotion to God (Arabic: Allah) all the more evident.
The Qur’an states that fasting was prescribed for those before them (i.e., the Jews and Christians) and that by fasting a Muslim gains taqwa, which can be described in one word as ‘Godconsciousness’ or ‘Godwariness’. Fasting is believed to help promote chastity and humility and prevent sin, the outburst of uncontrolled lusts and desires and far-fetched hopes. To Muslims, fasting acts as a shield with which the Muslim protects him/herself from jahannam (hell).
