Fasting

Fasting is primarily the act of willingly abstaining from some or all food, drink, or both, for a period of time. Concerning that from which one fasts, and the period of fasting, a fast may be total or partial. It may be observed unbroken for many uninterrupted days, or be observed only for certain periods during the day, as is the Muslim practice during the holy month of Ramadan. Depending on the tradition, fasting practices may preclude sexual activity as well as food, in addition to refraining from eating certain types or groups of foods; for example, one might refrain from eating meat. Medical fasting can be a way to promote detoxification.

Fasting for religious and spiritual reasons has been a part of human custom since pre-history. It is mentioned in the Bible, in both the Old and New Testament, the Qur'an, the Mahabharata, and the Upanishads. Fasting is also practiced in many other religious traditions and spiritual practices.

Fasting is also used in a medical context to refer to the state achieved after digestion of a meal. A number of metabolic adjustments occur during fasting and many medical diagnostic tests are standardized for fasting conditions. For most medical purposes a person is assumed to be fasting after 8-12 hours. A diagnostic fast refers to prolonged fasting (from 8-72 hours depending on age) conducted under medical observation for investigation of a problem, usually hypoglycemia. Fasting has occasionally been recommended as a therapeutic intervention by physicians of many cultures, though it is uncommonly resorted to for this purpose by modern doctors.

Bahá'í faith
In the Bahá'í Faith, fasting is observed from sunrise to sunset during the Bahá'í month of `Ala' (between March 2 through March 20). Bahá'u'lláh established the guidelines in the Kitáb-i-Aqdas. It is the complete abstaining from both food and drink (including abstaining from smoking). Observing the fast is an individual obligation, and is binding on all Bahá'ís who have reached the age of maturity, which is fifteen years of age.

Along with obligatory prayer, it is one of the greatest obligations of a Bahá'í. The Guardian of the Bahá'í Faith, 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."

Buddhism
Buddhist monks and nuns following the Vinaya rules commonly do not eat each day after the noon meal, though many orders today do not enforce this. This is not considered a fast, but rather a disciplined regiment aiding in meditation. Fasting is generally considered by Buddhists as a form of asceticism and as such is rejected as a deviation from the Middle way. However, the Vajrayana practice of Nyung Ne is based on the tantric practice of Chenrezig. It is said that Chenrezig appeared to Gelongma Palmo, an Indian nun who had contracted leprosy and was on the verge of death. Chenrezig taught her the method of Nyung Ne in which one keeps the eight precepts on the first day, then refrains from both food and water on the second. Although seemingly against the Middle Way, this practice is to experience the negative karma of both oneself and all other sentient beings and, as such, is seen to be of benefit. Other self-inflicted harm is discouraged.

Christianity
The "acceptable fast" is discussed in the biblical Book of Isaiah, chapter 58:3-7, and is discussed metaphorically. In essence, it means to abstain from satisfying hunger or thirst, and any other lustful needs we may yearn for. The blessings gained from this are claimed to be substantial. Christian denominations that practice this acceptable fast often attest to the spiritual principles surrounding fasting and seek to become a testament to those principles. The opening chapter of the Book of Daniel, vv. 8-16, describes a partial fast and its effects on the health of its observers. Fasting is a practice in several Christian denominations or other churches. Other Christian denominations do not practice it, seeing it as a merely external observance, but many individual believers choose to observe fasts at various times at their own behest, and the Lenten fast observed in Anglicanism is a forty day partial fast to commemorate the fast observed by Christ during his temptation in the desert.

Biblical accounts of fasting

 * Moses fasted for forty days and forty nights while he was on the mountain with God. (Exodus 34:28)
 * King David fasted when the son of his adulterous union with Bathsheba was struck sick by God, in punishment for the adultery and for David's murder of Bathsheba's husband, Uriah the Hittite. Nevertheless, the son died, upon which David broke his fast (2 Samuel 12:15-25).
 * King Jehosaphat proclaimed a fast throughout Judah for victory over the Moabites and Ammonites who were attacking them (2 Chronicles 20:3).
 * The prophet Isaiah chastised the Israelites in Isaiah 58 for the unrighteous methods and motives of their fasting. He clarified some of the best reasons for fasting and listed both physical and spiritual benefits that would result.
 * The prophet Joel called for a fast to avert the judgement of God.
 * The people of Nineveh in response to Jonah's prophecy, fasted to avert the judgement of God (Jonah 3:7).
 * The Jews of Persia, following Mordechai's example, fasted due to the genocidal decree of Haman. Queen Esther declared a three-day fast for all the Jews prior to risking her life in visiting King Ahasuerus uninvited (Esther 4).
 * The Pharisees in Jesus' time fasted regularly, and asked Jesus why his disciples did not. Jesus answered them using a parable (Luke 5:33-39, Matthew 9:14-15, Mark 2:18-20).
 * Jesus also warned against fasting to gain favor from men. He warned his followers that they should fast in private, not letting others know they were fasting (Matthew 6:16–18).
 * Jesus fasted for forty days and forty nights while in the desert, prior to the three temptations (Matthew 4:2, Luke 4:2).
 * Jesus said : But this kind (of demon) does not go out except by prayer and fasting. (Matthew 17:21)
 * And he (Jesus) said unto them (disciples), This kind (of demon) can come forth by nothing, but by prayer and fasting. (Mark 9:29)
 * The prophetess Anna, who proclaimed the birth of Jesus in the Temple, fasted regularly (Luke 2:37).
 * There are indications in the New Testament as well as from the Apocryphal Didache that members of the early Christian Church fasted regularly.

Charismatic
For Charismatic Christians fasting is undertaken at the leading of God. Fasting is done in order to seek a closer intimacy with God, as well as an act of petition. Some take up a regular fast of one or two days a week as a spiritual observance. Holiness movements, such as those started by John Wesley, Charles Wesley, and George Whitefield in the early days of Methodism, often practice such regular fasts as part of their regimen.

Eastern Orthodoxy & Eastern Catholicism

 * Main article: Eastern Orthodoxy: Fasting

For Eastern Orthodox and Eastern Catholics, there are four fasting seasons, which include Nativity Fast, Great Lent, Apostles' Fast and Dormition Fast.

Wednesdays and Fridays are also fast days throughout the year (with the exception of fast-free periods). In some Orthodox monasteries, Mondays are also observed as fast days (Mondays are dedicated to the holy Angels, and monasticism is called the "angelic life").

Fasting during these times also includes abstention from animal products (meat and often fish), olive oil (or all oils, according to some Orthodox traditions), and wine (which is interpreted as including all alcoholic beverages).

Fasting can take up a significant portion of the calendar year. The idea is not to suffer, but to use the experience to come closer to God, to realize one's excesses, and to engage in almsgiving. Fasting without increased prayer and almsgiving (donating to a local charity, or directly to the poor, depending on circumstances) is considered useless or even spiritually harmful by many Orthodox Christians.

Those desiring to receive Holy Communion keep a total fast from all food and drink from midnight the night before.

Certain festal periods are fast-free, meaning that fasting is forbidden, even on Wednesdays and Fridays (though fasting before Holy Communion is never relaxed, except for health reasons). These periods are:
 * The 12 days from the Nativity of Christ to Theophany (Epiphany)
 * The week following Pascha (Easter)—and during the 50 days from Easter Sunday to Pentecost, the fasting laws are lessened, wine and oil being permitted even on Wednesdays and Fridays
 * The week following Pentecost

Oriental Orthodox Churches
With exception of the Fifty days following Easter in the Coptic Orthodox Church fish is not allowed during Lent, Wednesdays, Fridays and Baramon days. Other than that Fish and Shellfish are allowed during Fasting days.

The discipline of fasting entails that apart from Saturdays, Sundays and Holy feasts should keep a total fast from all food and drink from midnight the night before to a certain time in the day usually Three O'clock in the afternoon (The hour Jesus died on the Cross), Also it is preferred to practice the reduction of one's daily intake of food (typically, by eating only one full meal a day).

Protestant churches
In Protestantism, the continental Reformers criticized fasting as a purely external observance that can never gain a person salvation. The Swiss Reformation of the "Third Reformer" Huldrych Zwingli began with an ostentatious public sausage-eating during Lent.

On the other hand, churches of the Anglican Communion and some American Protestant denominations, such as the United Methodist Church, affected by liturgical renewal movements encourage fasting as part of both Lent and Advent, two penitential seasons of the Liturgical Year.

Likewise, Lutheran churches encourage fasting during lent. They also encourage it before partaking in the Eucharist, as Luther writes in his Small Catechism: Who, then, receives such Sacrament worthily? Fasting and bodily preparation is, indeed, a fine outward training; but he is truly worthy and well prepared who has faith in these words: Given, and shed for you, for the remission of sins.

Members of the Anabaptist movement (e.g. Amish, Mennonite, Hutterite, et al.) generally fast, but in private. The practice is not regulated by ecclesiatic authority. 

Other Protestants consider fasting, usually accompanied by prayer, to be an important part of their personal spiritual experience, apart from any liturgical tradition. The United Methodist fast in the old Weslyean way of sundown to sundown on Mondays to Tuesdays and Thursdays to Fridays to promote discipline among Christ's followers.

Roman Catholicism
For Roman Catholics, fasting is the reduction of one's intake of food to one full meal (which may not contain meat during Fridays in Lent, only fish) and two small meals (known liturgically as collations, taken in the morning and the evening). Eating solid food between meals is not permitted. Fasting is required of the faithful on specified days. Complete abstinence is the avoidance of meat for the entire day. Partial abstinence prescribes that meat be taken only once during the course of the day. To some Roman Catholics, fasting still means consuming nothing but water.

Pope Pius XII had initially relaxed some of the regulations concerning fasting in 1956. In 1966, Pope Paul VI in his apostolic constitution Paenitemini, changed the strictly regulated Roman Catholic fasting requirements. He recommended that fasting be appropriate to the local economic situation, and that all Catholics voluntarily fast and abstain. In the United States, there are only two obligatory days of fast - Ash Wednesday and Good Friday. The Fridays of Lent are days of abstinence: those observing the practice may not eat meat. Pastoral teachings since 1966 have urged voluntary fasting during Lent and voluntary abstinence on the other Fridays of the year. The regulations concerning such activities do not apply when the ability to work or the health of a person would be negatively affected.

Prior to the changes made by Pius XII and Paul VI, fasting and abstinence were more strictly regulated. The church had prescribed that Roman Catholics observed fasting and/or abstinence on a number of days throughout the year.

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 some time before receiving the Eucharist during the Mass. 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.

The Church of Jesus Christ of Latter-day Saints
Latter-day Saint fasting is total abstinence from food and water. Adherents are encouraged to fast totally for two consecutive meal times once a month, and the first Sunday of the month is usually designated a Fast Sunday; some Latter-day Saints who observe the monthly fast begin the Saturday before this day by not partaking of the Saturday evening meal. Others abstain from breakfast and lunch on Fast Sunday. The importance should be placed on the attitude of one fasting, rather than on a legalistic debate over how long the fast should continue. The money saved by not having to purchase and prepare meals is to be donated to the church as a fast offering, which is to be used to help people in need. LDS President Gordon B. Hinckley asked: “What would happen if the principles of fast day and the fast offering were observed throughout the world[?] The hungry would be fed, the naked clothed, the homeless sheltered. … A new measure of concern and unselfishness would grow in the hearts of people everywhere.” (“The State of the Church,” Ensign, May 1991, 52–53.)

Sunday worship meetings on Fast Sunday include opportunities for church members to publicly express thanks and to bear their testimony of faith.

Because fasting involves exercising control of the physical body, subjugating it to the mind, many Latter-day Saints consider fasting a way to focus on the spiritual body, and use it in connection with prayer to make it more meaningful.

Hinduism
Fasting is a very integral part of the Hindu religion. Individuals observe different kinds of fasts based on personal beliefs and local customs. Some are listed below.
 * Some Hindus fast on certain days of the month such as Ekadasi or Purnima.


 * Certain days of the week are also set aside for fasting depending on personal belief and favorite deity.
 * Thursday fasting is very common among the Hindus of northern India. On Thursdays devotees listen to a story before breaking their fast. On the Thursday fasters also worship Vrihaspati Mahadeva or Jupiter. They wear yellow clothes, and meals with yellow colour are preferred. Women worship the banana tree and water it. Food items are made with yellow-coloured ghee.


 * Fasting during religious festivals is also very common. Common examples are Maha Shivaratri or the 9 days of Navratri (which occurs twice a year in the months of April and October/November during Vijayadashami just before Diwali, as per the Hindu calendar). Karwa Chauth is a form of fasting unique to the northern part of India where married women undertake a fast for the well-being, prosperity, and longevity of their husbands. The fast is broken after the wife views the moon through a sieve after sunset.

Methods of fasting also vary widely and cover a broad spectrum. If followed strictly, the person fasting does not partake any food or water from the previous day's sunset until 48 minutes after the following day's sunrise. Fasting can also mean limiting oneself to one meal during the day and/or abstaining from eating certain food types and/or eating only certain food types. In any case, even if the fasting Hindu is non-vegetarian, he/she is not supposed to eat or even touch any animal products (i.e. meat, eggs) on a day of fasting.

Islam
In Islam, fasting for a month is an obligatory practice during the holy month of Ramadan, from fajr (dawn), until maghrib (sunset). Muslims are prohibited from eating, drinking, smoking, and engaging in sexual intercourse while fasting. 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 their Lord by abandoning the things they enjoy, 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 as the care taken by a person to do everything God has commanded and to keep away from everything that He has forbidden. Fasting helps prevent many sins and is a shield with which the Muslim protects him/herself from jahannam (hell).

Muslims believe that fasting is more than abstaining from food and drink. It also includes abstaining from any falsehood in speech and action, from any ignorant and indecent speech, and from arguing and fighting, and lustful thoughts. Therefore, fasting helps develop good behavior.

Fasting also inculcates a sense of fraternity and solidarity, as Muslims feel and experience what their needy and hungry brothers and sisters feel. However, even the poor, needy, and hungry participate in the fast. Moreover, Ramadan is a month of giving charity and sharing meals to break the fast together.

While fasting in the month of Ramadan is considered Fard (obligatory), Islam also prescribed certain days for non-obligatory, voluntary fasting, such as:


 * each Monday and Thursday of a week
 * the 13th, 14th, and 15th day of each lunar month
 * six days in the month of Shawwal (the month following Ramadan)
 * the Day of Arafat (9th of Dhu al-Hijjah in the Hijri (Islamic calendar))
 * the Day of Ashura (10th of Muharram in the Hijri calendar), with one more day of fasting before or after it

Although fasting is fard, exceptions are made for persons in particular circumstances:
 * Prepubescent children; though some parents will encourage their children fast earlier for shorter periods, so the children get used to fasting.
 * Serious illness; the days lost to illness will have to be made up after recovery.
 * If one is traveling, since the fajr and maghrib times will change; but one must make up any days missed upon arriving at one's destination.
 * Women who are pregnant or nursing.
 * A woman during her menstural period; although she must count the days she missed and make them up at the end of Ramadan.

Jainism
There are many types of fasting in Jainism. One is called Chauvihar Upwas, in which no food or water may be consumed until sunrise the next day. Another is called Tivihar Upwas, in which no food may be consumed, but boiled water is allowed. The main goal of any type of Fasting in Jainism is to achieve complete Non-Violence(दया)during that period. Fasting is usually done during Paryushana but can be done during other times. If one fasts for the eight days of Paryushana, it is called Atthai, and when it is for One Month, it is known as Maskhamana. Also, it is common for Jains not to fast but only to limit their intake of food. When a person only eats lentils and tasteless food with salt and pepper as the only spices, the person is said to do Ayambil. This is supposed to decrease desire and passion. Self-starvation by fasting is known as Sallekhana and is supposed to help shed karma according to Jain philosophy.

Another form of fasting is Santhara, the Jain religious ritual of voluntary death by fasting. Supporters of the practice believe that Santhara cannot be considered suicide, but rather something one does with full knowledge and intent, while suicide is viewed as emotional and hasty. Due to the prolonged nature of Santhara, the individual is given ample time to reflect on his or her life. The vow of Santhara is taken when one feels that one's life has served its purpose. The goal of Santhara is to purify the body and, with this, the individual strives to abandon desire.

Judaism
Fasting for Jews means completely abstaining from food and drink, including water. Brushing teeth is forbidden on the major fast days of Yom Kippur and Tisha B'Av (See below), but permitted on minor fast days. Taking medications is generally not permitted, except where a doctor's orders would forbid abstaining. Observant Jews fast on up to six days of the year. With the exception of Yom Kippur, fasting is never permitted on Shabbat, for the commandment of keeping Shabbat is biblically ordained and overrides the later rabbinically-instituted fast days. Yom Kippur is the only fast day which is explicitly stated in the Torah.

Yom Kippur is considered to be the most important day of the Jewish year and fasting as a means of repentance is expected of every Jewish man and boy above the age of bar mitzvah and every Jewish woman and girl above the age of bat mitzvah. It is so important to fast on this day, that only those who would be put in danger by fasting are exempt, such as the ill, elderly, or pregnant or nursing women, as endangering one's life is against a core principle of Judaism. Those that do eat on this day are encouraged to eat as little as possible at a time and to avoid a full meal. For some, fasting on Yom Kippur is considered more important than the prayers of this holy day. If one fasts, even if one is at home in bed, one is considered as having participated in the full religious service. In addition to fasting and prayer, Yom Kippur -- as the "Sabbath of Sabbaths" -- has the same restrictions regarding work as the Sabbath, such as striking a fire, carrying objects outside the home, using tools, and so on. Recreational activities are permitted, even when those activities would otherwise constitute "work", such as writing, exercising, etc.. Traditionally, leather shoes are not worn on this day. Men may wear a white gown (kittel) over their clothes, symbolic of a burial shroud on this Day of Judgement. Women may either wear all white, or they may simply wear a large white scarf over their heads, and many do not put on make-up or jewelry. The aura of the day is serious, humble, sacred and repentant, yet happy in the knowledge that sincere repentance brings redemption.

The second major day of fasting is Tisha B'Av, the day nearly 2000 years ago on which the Romans destroyed the Holy Temple in Jerusalem and the Jews were banished from their homeland. Tisha B'Av ends a period of nine days in which Jews do not participate in happy events, wash clothes, eat meat except on the Sabbath, cut hair or swim. In general, these nine days and to some extent the entire three weeks before Tisha B'Av are considered a time of risk for Jews. Historically, this timeframe has been rife with persecutions and other tragic events. Unlike the fast of Yom Kippur, there are no restrictions on activities, although one should try to avoid doing regular work the first part of the day, sit in a low chair or on the floor, and wear no leather shoes. This is also the day when observant Jews remember the many tragedies which have befallen the Jewish people, including the Holocaust. The atmosphere of this holiday is serious and deeply sad.

Both of these holy days are considered major fasts and are observed from sunset to sunset the following day by both men and women. The remaining four fasts are considered minor and fasting is only observed from sunrise to sunset. Men are expected to observe them, and women should observe them, but a rabbi may often give dispensions if the fast represents too much of a hardship to a sick or weak person.

The minor fast days are:
 * The Fast of Gedaliah
 * The Fast of the 10th of Tevet
 * The Fast of the 17th of Tammuz,
 * The Fast of Esther, which takes place immediately before Purim

Additional fast days such as the Fast of the Firstborn, which only applies to first-born sons; family-instituted fasts in remembrance of a miraculous delivery from tragedy, which only apply to certain families or to certain regions; communal fasts in the face of impending calamity in order to arouse benevolence from the Heavens; or personal fasts as a means of repentance are not undertaken by the entire Jewish community.

On the two major fast days it is also forbidden to engage in any sexual relations.

Aside from these official days of fasting, Jews may take upon themselves personal or communal fasts, often to seek repentance in the face of tragedy or some impending calamity. For example, a fast is observed if the scrolls of the Torah are dropped. The length of the fast varies, and some Jews will reduce the length of the fast through tzedakah, or charitable acts.

It is traditional for a bride and groom to fast on their wedding day before the ceremony as the day represents a personal Yom Kippur. In some congregations, repentance prayers that are only said on Yom Kippur are included by the bride and groom in the service before the ceremony.

Purpose of fasting in Judaism
Judaism views three essential potential purposes of fasting, and a combination of some or all of these could apply to any given fast. One purpose in fasting is the achievement of atonement for sins and omissions in Divine service. Fasting is not considered the primary means of acquiring atonement; rather, sincere regret for and rectification of wrongdoing is key (see Isaiah, 58:1-13, which appropriately is read as the haftorah on Yom Kippur).

Nevertheless, fasting is conducive to atonement, for it tends to precipitate contrition in the one who fasts (see Joel, 2:12-18). This is why the Bible requires fasting (lit. self affliction) on Yom Kippur (see Leviticus, 23:27,29,32; Numbers, 29:7; Tractate Yoma, 8:1; ibid. (Babylonian Talmud), 81a). Because, according to the Hebrew Bible, hardship and calamitous circumstances can occur as a result of wrongdoing (see, for example, Leviticus, 26:14-41), fasting is often undertaken by the community or by individuals to achieve atonement and avert catastrophe (see, for example, Esther, 4:3,16; Jonah, 3:7). Most of the Talmud's Tractate Ta'anit ("Fast[s]") is dedicated to the protocol involved in declaring and observing fast days.

The second purpose in fasting is commemorative mourning. Indeed, most communal fast days that are set permanently in the Jewish calendar fulfil this purpose. These fasts include: Tisha B'Av, Seventeenth of Tammuz, Tenth of Tevet (all of the three dedicated to mourning the loss of the destroyed Temple in Jerusalem), and Fast of Gedaliah. The purpose of a fast of mourning is the demonstration that those fasting are impacted by and distraught over earlier loss. This serves to heighten appreciation of that which was lost. This is in line with Isaiah (66:10), who indicates that mourning over a loss leads to increased happiness upon return of the loss:


 * Be glad with Jerusalem, and exult in her, all those who love her; rejoice with her in celebration, all those [who were] mourners over her.

The third purpose in fasting is commemorative gratitude. Since food and drink are corporeal needs, abstinence from them serves to provide a unique opportunity for focus on the spiritual. Indeed, the Midrash explains that fasting can potentially elevate one to the exalted level of the Mal'achay HaSharait (ministering angels) (Pirkei d'Rabbi Eliezer, 46). This dedication is considered appropriate gratitude to God for providing salvation. Additionally, by refraining from such basic physical indulgence, one can more greatly appreciate the dependence of humanity on God, leading to appreciation of God's benificience in sustaining His creations. Indeed, Jewish philosophy considers this appreciation one of the fundamental reasons for which God endowed mankind with such basic physical needs as food and drink. This is seen from the text of the blessing customarily recited after consuming snacks or drinks:


 * You are the Source of all blessing, O' Eternal One, our God, King of the universe, Creator of many souls, who gave [those souls] needs for all that which You created, to give life through them to every living soul. Blessed is the Eternal Life-giver.

Sikhism
Sikhism is probably the only major organised world religion that does not promote fasting except for medical reasons. The Sikh Gurus discourage the devotee from engaging in this ritual as it is considered to "brings no spiritual benefit to the person". The Sikh holy Scripture, Sri Guru Granth Sahib tell us: "Fasting, daily rituals, and austere self-discipline - those who keep the practice of these, are rewarded with less than a shell."(SGGS page 216). So most Sikhs have never undertaken a fast of any kind.

Medical fasting
People can also fast for medical reasons, which has been an accepted practice for many years. One reason is to prepare for surgery or other procedures that require anesthetic. Because the presence of food in a person's system can cause complications during anesthesia, medical personnel strongly suggest that their patients fast for several hours (or overnight) before the procedure.

Another reason for medical fasting is for certain medical tests, such as cholesterol testing (lipid panel). People are often asked to fast so that a baseline can be established. In the case of cholesterol, the failure to fast for a full 12 hours (including vitamins) will guarantee an elevated Triglyceride measurement.

A longer fast for health reasons typically lasts a week or longer and includes some food intake, such as fruit or vegetable juices, as part of a detox diet.

Some doctors believe that pure water fasting can not only detoxify cells and rejuvenate organs, but can relieve such diseases and conditions as cardiovascular disease, rheumatoid arthritis, asthma, high blood pressure, type 2 diabetes, colitis, psoriasis, lupus and some other autoimmune disorders when combined with a healthy diet. They believe that "Fasting is Nature's Restorer."

Recent studies on mice show that fasting every other day while eating double the normal amount of food on non-fasting days led to improved insulin and blood sugar control, neuronal resistance to injury, and health indicators superior to mice on 40% calorie restricted diets. Alternate day calorie restriction may prolong lifespan and attenuates diseases associated with inflammation, oxidative stress and aging.

People who feel they are near the end of their life sometimes consciously refuse food or water. The term in the medical literature is patient refusal of nutrition and hydration. Contrary to popular impressions, published studies indicate that "within the context of adequate palliative care, the refusal of food and fluids does not contribute to suffering among the terminally ill", and might actually contribute to a comfortable passage from life: "At least for some persons, starvation does correlate with reported euphoria."

In natural medicine, fasting is seen as a way of cleansing the body of toxins, dead or diseased tissues, and giving the gastro-intestinal system a rest. Such fasts are either water-only, or consist of fruit and vegetable juices. Some results have been achieved while including fasting in the treatment of some kinds of cancer, autoimmune diseases, and allergies.

Common terms used in research are: reduced diet therapy (RDT), Fasting Therapy (FT) and caloric restriction. Research tends to originate from Russia, Japan and Germany.

Ayurveda describes fasting therapy as langhana which is an important treatment tool used with other therapeutic methods like heat therapy and oil therapy.

Physiological effects of fasting
See Famine response for the body's energy requirements and the changes in energy metabolism induced by fasting.

When food is not eaten, the body looks for other ways to find energy, such as drawing on glucose from the liver's stored glycogen and fatty acids from stored fat and eventually moving on to vital protein tissues. Body, brain and nerve tissue depend on glucose for metabolism. Once the glucose is significantly used up, the body's metabolism changes, producing ketone bodies (acetoacetate, hydroxybutyrate, and acetone). Even where this transition to alternative forms of energy has been made, some parts of the brain still require glucose, and protein is still needed to produce it. If body protein loss continues, death will ensue.

Fasting in literature

 * Franz Kafka's short story A Hunger Artist (Ein Hungerkünstler - 1922) describes a man who fasts as a form of art or theatre.
 * Siddhartha by Hermann Hesse (Siddhartha - 1922). Siddhartha lists his three skills - 'I can think, I can wait, I can fast'
 * The Rule of St Benedict and a vast body of ascetic writings, speak in great detail about fasting.

Other

 * The Bridegroom Fast - This fast was initiated by the leaders of the International House of Prayer, and is observed on the first Monday, Tuesday, and Wednesday of each month. Based on Matthew 9:15, its focus is intimacy with Christ, who is described in the Bible as the bridegroom of the Church.  The fast is accompanied by services in Kansas City, which are freely accessible by webcast.  It is observed largely in charismatic circles.
 * Jeûne genevois (lit. "fast of Geneva") is a public holiday and day of fasting in the canton of Geneva, Switzerland, occurring on the Thursday following the first Sunday of September.

Pros

 * reduction of serum lipid concentrations in blood, hence having a low risk of obesity.

Cons

 * increases the likelihood of acetaminophen poisoning, possibly because of depletion of hepatic glutathione reserves.