This post is a continuation of our primary post on How to Start Fasting, which is a good place to start to learn the purpose and first steps of learning how to fast. This post will tell you give you some tips on dealing with the physical dynamics of fasting.
The following is an excerpt from Richard Foster's Celebration of Discipline (New York: HarperCollins, 1998):
Contemporary men and women are largely ignorant of the practical aspects of fasting. Those who desire to fast need to acquaint themselves with this basic information.
As with all the Disciplines, a progression should be observed; it is wise to learn to walk well before we try to run. Begin with a partial fast of twenty-four hours’ duration; many have found lunch to lunch to be the best time. This means that you would not eat two meals. Fresh fruit juices are excellent to drink during the fast. Attempt this once a week for several weeks. In the beginning you will be fascinated with the physical aspects of your experience, but the most important thing to monitor is the inner attitude of the heart. Outwardly you will be performing the regular duties of your day, but inwardly you will be in prayer and adoration, song, and worship. In a new way, cause every task of the day to be a sacred ministry to the Lord. However mundane your duties, for you they are a sacrament. Cultivate a “gentle receptiveness to divine breathings.” Break your fast with a light meal of fresh fruits and vegetables and a good deal of inner rejoicing.
After two or three weeks you are prepared to attempt a normal fast of twenty-four hours. Drink only water but use healthy amounts of it. Many feel distilled water is best. If the taste of water bothers you, add one teaspoon of lemon juice. You will probably feel some hunger pangs or discomfort before the time is up. That is not real hunger; your stomach has been trained through years of conditioning to give signals of hunger at certain hours. In many ways the stomach is like a spoiled child, and a spoiled child does not need indulgence, but needs discipline. Martin Luther says “. . . the flesh was wont to grumble dreadfully.” You must not give in to this “grumbling.” Ignore the signals, or even tell your “spoiled child” to calm down, and in a brief time the hunger pangs will pass. If not, sip another glass of water and the stomach will be satisfied. You are to be the master of your stomach, not its slave. If family obligations permit it, devote the time you would normally use eating to meditation and prayer. . . .
After having achieved several fasts with a degree of spiritual success, move on to a thirty-six-hour fast: three meals. With that accomplished, it is time to seek the Lord as to whether he wants you to go on to a longer fast. Three to seven days is a good time period and will probably have a substantial impact on the course of your life. . . .
Although the physical aspects of fasting intrigue us, we must never forget that the major work of scriptural fasting is in the realm of the spirit. What goes on spiritually is much more important than what is happening bodily. You will be engaging in spiritual warfare that will necessitate using all the weapons of Ephesians 6. One of the most critical periods spiritually is at the end of the fast when we have a natural tendency to relax. But I do not want to leave the impression that all fasting is a heavy spiritual struggle—I have not found it so. It is also “. . . righteousness and peace and joy in the Holy Spirit” (Rom. 14:17).
Fasting can bring breakthroughs in the spiritual realm that will never happen in any other way. It is a means of God’s grace and blessing that should not be neglected any longer.