Fasting has been practiced for thousands of years, and is especially common as a spiritual exercise in many religions. Scientific studies have shown that there are also physical benefits that include reducing risk of diabetes, heart disease, and cancer. Fasting also promotes weight loss, reduces immune disorders, and slows the aging process—increasing life span. It will produce favorable change in cholesterol.
Each year, as the time of fasting approaches, I begin to eagerly anticipate it. I am happy, and also feel slight trepidation, knowing I will be tested. I wake before dawn and eat . . . my body still drowsy and not ready for food—so I must assert command to change for the sake of devotion. As the day progresses I experience weakness and loss of concentration, and this is because of lack of glucose and protein. Tasks become more difficult and I realize I am multi-tasking because I am simultaneously active with my affairs and also fasting. I get moody and perhaps even cranky as time goes on, and must adopt a sense of equanimity, a virtue useful to all rational thought. When my hunger and thirst press upon me and I know how easy it is to eat or drink and relieve my suffering, instead, I practice will power and patience. Nineteen days is a hefty duration and this deepens all the positive lessons.
These are some of the virtues found in fasting: patience, moderation, temperance, fortitude, will power, devotion, ability to sacrifice, forbearance, bravery, commitment, creativity, detachment, discretion, enthusiasm, flexibility, love, grace, tolerance, honor, integrity, loyalty, perseverance, resourcefulness, simplicity, sincerity, trust. Add to the spiritual virtues the physical benefits of better health and longer life and we can see why fasting is an ancient and common global practice.
Here is a wonderful and in-depth article on fasting: The Ultimate Guide to Intermittent Fasting