After trying it for himself, the Buddha is believed to have asserted that extreme fasting runs contrary to the Buddhist path. While relatively short-term, supervised fasts are sometimes undertaken as an aid to meditation in all three of the major Buddhist traditions, no clearly defined rules are in place. The ways with which the practice is carried out are largely determined by individual practitioners and their spiritual teachers. The historical Buddha's example shows that moderation, not rejection, of food is a necessary element of Buddhist practice.

The role of fasting in the Buddha's life

Before Siddhartha Gautama became the Buddha, he is said to have undertaken extreme ascetic practices in the hopes of reaching enlightenment. An early scripture known as the Mahavastu relates that for several years, Siddhartha ate only a single sesame seed and one berry per day. The Buddha became so emaciated that his eyes sunk deep into his skull, but his meditation did not progress as a result. As the story goes, he finally accepted nourishment when offered a bowl of milk porridge. From this point, he is said to have regained his strength and sat in meditation until he realized enlightenment.

The Middle Way

After his enlightenment, the Buddha taught moderation in food as a "middle way" between deprivation and gluttony. This is a constant theme among all Buddhist schools and it is reflected in rules relating to food. In the Mahayana and Vajrayana traditions, monastics typically eat two or three light vegetarian meals per day. In the Theravada tradition, monastics abstain from eating solid food after noon and many eat only one small meal per day. While the emphasis is on moderation in food, fasting does play a background role in all Buddhist traditions, though not for all practitioners.

The Theravada tradition

In the Theravada tradition of south and southeast Asia, monastics occasionally fast as part of extended meditation practice. The goal is to understand craving in an experiential way and, ideally, to reach a state in which the mind is at peace in spite of the body's discomfort. Fasts are always supervised and the eldest monastic in a given monastery typically dictates the length of time that a younger monastic can fast. Durations of fasts are flexible and generally depend on how the monastic responds to the practice. Fasting is particularly common in disciplined meditation sects, but the decision to fast is entirely up to each individual.

The Mahayana tradition

Monastics in east Asian Mahayana Buddhist schools occasionally fast for periods of 18, 36 and sometimes up to 72 days. As in the Theravada, the practice is undertaken in correlation with extended periods of meditation. The goals are to purify the body, increase mental clarity and cultivate wisdom while experiencing the effects of craving on the mind. The practice is always supervised by other monastics and is by no means a requirement of the tradition.

The Vajrayana tradition

In the Tibetan Vajrayana tradition, it is fairly common for adherents to undertake two-day long fasts as part of the Ngyungne ceremony which also incorporates chanting and meditation and is believed to purify both the body and negative karma. Experienced practitioners occasionally fast for longer periods, often while pursuing tantric goals such as increasing the body's heat level or simulating the body's deterioration leading up to death. As with the Theravada and Mahayana, fasting is not required and rules governing it are largely up to the superiors of individual practitioners.

Fasting by Buddhist lay-practitioners

It is unusual for non-monastics to undertake long-term fasts in any Buddhist tradition. However, many lay-practitioners often join monastics in foregoing food on "uposatha" days, or holy full moon observances, though fasting at these times is not required even for monastics. On one day per week, many lay-practitioners avoid eating meat or eating after noon. In all traditions, both monastics and lay-practitioners are allowed to drink water and other fluids throughout a fast and to quit at any time.