i would like to have more details on fasting, which many religions have specified
—venkatesh, south India
I apologize for taking over a week to reply to your question regarding fasting. It’s such a broad topic that I wanted to give it appropriate consideration.
As you indicate, many spiritual traditions utilize fasting for physical, mental and spiritual purification. An important purpose of fasting is to overcome greed for food and to eliminate both mental and physical toxins. Ideally when we fast for spiritual reasons, we have more time to fully concentrate with devotion uplifted for inner communion with the Divine because we are less engaged in food preparation, cooking and digestion.
There are many ways to fast and I recommend when you fast that you also give yourself a mental fast free from worries, negative thoughts and encumbering preoccupations to allow your soul to soar in inner freedom. Make it a devotional practice of celebration for the blessings you receive in your life as well as an inward act of self offering to God.
For further information on fasting as taught by Paramhansa Yogananda, I recommend The Wisdom of Yogananda book, How To Achieve Glowing Health and Vitality (also available in the U.S. and around the world). There are various types of fasts mentioned in the book which may give you insight, inspiration and guidance.
It is advisable to have a physician determine if there are any contraindications for you if you are considering a prolonged fast.
God Bless you,