Water fasting

Water fasting is a type of fasting in which the practitioner consumes only water. One may water fast for a variety of reasons, including medical and religious requirements. Such fasting for prolonged periods poses significant health risks.

Health effects

Some engage in water fasting as a detox diet. While there is no established body of scientific evidence showing that any detoxification occurs because of water fasting, there is evidence of harmful side effects from such diets.

The excessive intake of water without the corresponding amount of electrolytes can lead to hyponatraemia, also known as water intoxication. This can lead to permanent brain damage, coma and death. It is recommended to do water fasting under a doctor's supervision, especially the first time because some people are unable to do it because of metabolic issues. Some rare metabolic issues can cause death during water fasting.

Research published by ALN (and others from an article in Stem Cell Stem) indicates that there is good health reasons for a water fast. In the 2014 article from ALN, Suzanne Wu states that "cycles of prolonged fasting not only protect against immune system damage — a major side effect of chemotherapy — but also induce immune system regeneration, shifting stem cells from a dormant state to a state of self-renewal." During water fasting, no energy is spent on digestion other than to heat any cold water to reach homeostasis of a uniform body temperature. The fast is normally undergone with the belief that it can bring about detoxification for greater health. The reasoning is that less energy is expended on digestion of foods, resulting in more energy for the rest of the body to expel toxins as well as to recover and heal itself from the stresses digestion places upon it. Paul C. Bragg referred to this energy as the "Vital Force," and popularized water fasting with his many books including Bragg Health Crusades, and promotion by Hollywood celebrities such as Stephanie Morgan and Clint Eastwood. Other proponents claim that protein sparing minimizes muscle loss as the body adapts to the lack of incoming protein by drawing upon almost solely fat for energy. Even so, metabolism will slow during an extended fast and physical/mental activity should be minimized for safety reasons.

Weight loss

Water fasting is arguably one of the fastest weight loss methods in existence, because the caloric intake during a water fast is in fact zero. Without food, our bodies are forced to rely on our body fat reserves for energy almost exclusively, although they can't do so with a 100% efficiency. The limit on how quickly energy can be released from body fat stores has been determined at about 31 calories per pound of body fat per day.

Restricting calories beyond that limit causes a decrease of fat-free body mass as well. A weight loss rate of almost 3 pounds per day was achieved in a water fasting weight loss experiment, while less than half of the lost weight were actual body fat losses. Everything else was fat-free mass, which included water released from glycogen stores depletion, water released because of zero-sodium intake, muscle tissue breakdown and the emptying of the colon.

Medical requirement

Historically, many surgeries and general anaesthetics required a patient to fast for up to half a day before the procedure. This is thought to reduce potential complications of stomach volume and acidity during the procedure. However, growing research suggests that patients, especially children, may do better if they consume water or clear liquid during the final hours of this fast.

Religious requirement

Jainism

Jains maintain a strict water-only fast for 8 days, during the days of Paryushan. The warm water consumed should be only between sunrise and sunset and not during the night, since night is a highly-susceptible time for micro-organismic activity. For Jains fasting is a way of penance.

Roman Catholicism

Roman Catholics must engage in the Eucharistic Fast, which is a water fast before receiving the Eucharist during the Mass. While no nutritional or caloric sustenance is permitted, practitioners may take medicine if required, and those whose health problems impede them from taking part in the fast are dispensed of the obligation.

Up until the reforms of the Second Vatican Council, this fast was required from the previous midnight, as it is in various Orthodox Churches. However, under Pope Paul VI, the obligatory fast was reduced to only one hour before receiving the Eucharist.

The Catholic Church has also promoted a Black Fast, in which in addition to water, bread is consumed. Typically, this form of fasting was only used by monks and other religious individuals who practice mortifications and asceticism, but all Catholics are invited to take part in it with the advice and consent of their Spiritual Director.

See also

• Juice fasting
• Calorie restriction
• Intermittent fasting