Why do We Fast?As per the scriptures, fasting helps create an attunement with the Absolute by establishing a relationship between body and soul. This is thought to be imperative for the well being of a human being as it nourishes one's physical and spiritual demands.
Fasting in Sanskrit is called upavaasa. Upa means "near" + vaasa means "to stay". Upavaasa therefore means staying near (the Lord). However, fasting is not only a part of worship, but a great instrument for self-discipline too. It is a training of the mind and the body to endure and harden up against all hardships, to persevere under difficulties and not give up.
According to Hindu Philosophy, When the stomach is full, the intellect begins to sleep. Wisdom becomes mute and the parts of the body restrain from acts of righteousness. Fasting helps us to cultivate control over our senses, sublimate our desires and guide our minds to be poised and at peace.
Fasting, apart from its spiritual benefits, is a blessing to one's system as well. A change in the food intake and rest during fasting is good for the digestive system. A break for the digestive system only aids in functioning of it more efficiently. However the process of fasting loses its purpose when one gets irritable, weak and attains the urge to indulge later. This often happens when there is not a noble drive behind or when one goes about with a mechanical outlook.
The Bhagavad-Gita urges us to eat appropriately - yukta-aahaara (neither too less nor too much) and to eat simple, pure and healthy food (a saatvik diet) even when not fasting.
Yoga and Ayurveda stress on fasting for physical and spiritual well-being. When the digestive system is rested, it burns off existing toxins in the intestines. The lightness of being that is experienced leads towards spiritual clarity. Sipping decoctions of digestive ingredients like black pepper, ginger and jaggery further cleans up the body.
The underlying principle behind fasting is to be found in Ayurveda. This ancient Indian medical system sees the basic cause of many diseases as the accumulation of toxic materials in the digestive system. Regular cleansing of toxic materials keeps one healthy. By fasting, the digestive organs get rest and all body mechanisms are cleansed and corrected. A complete fast is good for heath, and the occasional intake of warm lemon juice during the period of fasting prevents the flatulence.
Since the human body, as explained by Ayurveda, is composed of 80% liquid and 20% solid, like the earth, the gravitational force of the moon affects the fluid contents of the body. It causes emotional imbalances in the body, making some people tense, irritable and violent. Fasting acts as antidote, for it lowers the acid content in the body which helps people to retain their sanity.
Research suggests there are major health benefits to caloric restriction. Benefits include reduced risks of cancer, cardiovascular diseases, diabetes, insulin resistance, immune disorders, and more generally, the slowing of the aging process, and the potential to increase maximum life span. Besides these health benefits, there is a potential link between fasting and improved efficacy of chemotherapy.