all income site .Fasting is a willing abstinence or reduction from some or all food, drink, or both, for a period of time. An absolute fast (dry fasting) is normally defined as abstinence from all food and liquid for a defined period, usually a period of 24 hours. Water fasting allows drinking water but nothing else. Other fasts may be partially restrictive, limiting only particular foods or substances. A fast may also be intermittent in nature. Fasting practices may preclude intercourse and other activities as well as food. In a physiological context, fasting may refer to the metabolic status of a person who has not eaten overnight, or to the metabolic state achieved after complete digestion and absorption of a meal. metabolic adjustments occur during fasting, and some diagnostic tests are used to determine a fasting state. Metabolic changes toward the fasting state begin after absorption of a meal; ’post-absorptive state’ is synonymous with this usage, in contrast to the postprandial state of ongoing digestion. A diagnostic fast refers to prolonged fasting (from 8–72 hours depending on age) conducted under observation for investigation of a problem, usually hypoglycemia. Many people may also fast as part of a medical procedure or check-up such as a colonoscopy. Fasting is also a part of many religious rituals.