Q: Alright guys, I'm 18 and I don't know how to properly fast. Now after you're done laughing, can somebody give me a step by step list of how to start it, end it and anything else that I need to know?
A: I applaud you for your desire to learn how to fast properly. When done correctly, fasting is an opportunity to grow closer to the Lord and to grow stronger spiritually.
How to fast
As a matter of custom, the Church typically designates the first Sunday of every month as a day of fasting. In order to properly observe ‘fast Sunday’ you should “go without food and drink for two consecutive meals, [attend] fast and testimony meeting, and [give] a fast offering to help care for those in need” (Gospel Topics: Fasting and Fast Offerings, lds.org). You are not restricted to fasting only on ‘fast Sundays’ however. In fact, it is perfectly appropriate to fast on other days, as long as you do not “fast too frequently or for excessive periods of time” (Gospel Topics: Fasting and Fast Offerings, lds.org). The actual process of observing a fast is a relatively simple one; however I feel I should point out that, if you want to do it properly, there is a little more to fasting than just a step-by-step process.
First, it’s important to remember that proper fasting is always accompanied by sincere prayer. In a way you could say that fasting is not a standalone principle, but that it depends on the related principle of heartfelt prayer in order to function properly. Prayer is not always accompanied by fasting, but fasting should always be coupled with prayer. I think that people too often forget that fasting (when coupled with prayer) is a profound way to worship God and to express our devotion and gratitude to Him. We have also been instructed to “begin and end our fasting with prayer” (Gospel Principles, (2011), 144–48).
Fasting with a purpose
We have also been instructed to “fast with a purpose,” which means that “We can overcome weaknesses or problems by fasting and praying. Sometimes we may wish to fast and pray for help or guidance for others, such as a family member who is ill and needs a blessing (see Mosiah 27:22–23)” (Gospel Principles, (2011), 144–48).
Fasting is a powerful means by which we can seek for the welfare of others and not just for our own needs.
Alma 6:6 Nevertheless the children of God were commanded that they should gather themselves together oft, and join in fasting and mighty prayer in behalf of the welfare of the souls of those who knew not God.
While we may choose to fast for many purposes, Elder L. Tom Perry, of The Quorum of the Twelve Apostles, taught that there are three main purposes behind the law of the fast itself: “The law of the fast has three great purposes. First, it provides assistance to the needy through the contribution of fast offerings, consisting of the value of meals from which we abstain. Second, a fast is beneficial to us physically. Third, it is to increase humility and spirituality on the part of each individual” (L. Tom Perry, “The Law of the Fast,” Ensign, May 1986).