Long term fasting can be safe, even healthy, if supervised by a trained physician. There are several types of fasting used to both prevent and treat disease. Many doctors recommend fasting as a method to free the body from toxins. Although some critics claim that the body cannot tell the difference between starvation and fasting, other doctors insist that fasting and starvation are two separate processes.
There is some debate on how many days a fast must last to be considered long term fasting. Some people believe that anything over three days is long term, while others think a long term fast will stretch past 30 days. Many factors influence how quickly a fast will affect the body, such as body weight and metabolism. The line that separates a short-term fast from a long-term fast might be different for each individual.
Experts recommend consulting a doctor if a fast will last longer than three days. If a person intends to fast for longer than three days, most doctors will recommend regular checkups to ensure that the patient's electrolyte and potassium levels do not drop. The doctor will help his patient decide how closely the fast should be monitored.
A doctor might ask his patient to discontinue long term fasting if any signs of starvation begin to occur. Although fasting can sometimes last several months, it is not considered safe for the body to reach starvation mode. A healthy body can usually last at least 40 days without experiencing signs of starvation, even with little body fat. Signs of starvation include vomiting, anxiety, heartburn, difficulty breathing or a weak pulse.
Several different kinds of fasting are available. The most extreme is called a dry fast, which does not permit any food or water. A dry fast is usually not recommended for long term fasting, although it can be incorporated into a few days. Water only fasting is another option. During this fast, no calories are ingested, but water is still consumed regularly.
Juice fasting is also a common practice. People can still maintain a minimal calorie intake without eating any food. The easiest fast focuses on just one kind of food, such as raw food only. A raw food fast might supply a normal calorie intake, but its participants will still go through a detox period.
Doctors typically do not recommend long term fasting for children or pregnant women, because daily nutrients are needed for growing bodies. Fasting might also be discouraged for people suffering from certain diseases, such as cancer, AIDS or tuberculosis. Fasting might actually help with other ailments such as fatigue, arthritis, diabetes, insomnia or the flu. Fasting is also done in some religious practices.