A fast is a period of deliberate abstinence from food and/or drink, usually as a religious observance. In period, many Christians would fast regularly as a form of self-mortification to purify their souls.
Fasting was also a feature of the Roman Catholic season of Lent, the forty days preceding Easter, when Catholics traditionally shun meat. Jews have six fast days in their calendar, including Yom Kippur and Tisha B'Av. Fasting is also practiced in Islam: during the month of Ramadan Muslims are to abstain from eating, drinking and sexual congress between sunrise and sunset.