"The purpose of fast days is to achieve a certain mood or state of mind (not self-torture). The prophets mention the obligation to mourn the exile through fasting, but they stress that the fast is primarily a means to gather the entire community together for prayer.
The end result of a day of fasting should be self-improvement and positive change, or at the very least, acknowledgment that there is a need for change. The external aspects of the fast days are important, but the internal aspects are even more critical. If a person observes the fast meticulously, does not let a drop of water pass his lips or a crumb of bread enter his mouth, but does not engage in reflection or introspection, he or she has missed the point.
Fasting for an entire day is certainly not pleasant, but this unpleasantness helps us to identify with the suffering of our fellow Jews throughout the exile. Through this process we should be inspired to improve our lives and become better people.
