An absolute fast withholds both food and liquid. This may be done for religious purposes, such as during the holy month of Ramadan in the Muslim tradition. During that time, no food or drink is consumed during the period between sunrise and sunset. Medically, this combines the food restriction of fasting with dehydration due to the restriction of fluids. This makes an absolute fast much more physically difficult and limits the duration to fairly short periods. Absolute fasts are not generally recommended for health purposes.
