Why do we fast? What is the purpose of fasting?

Fasting (going without food and drink for a period of time) is an ancient practice. We believe it must have existed among believers from the very beginning. The purposes of fasting include:

Developing spiritual strength, including resisting temptation.
Developing self-mastery, making our spirits masters of our bodies.
Showing humility.
Showing sorrow.
Enhancing prayer.
Obtaining spiritual knowledge and testimony.
Obtaining spiritual guidance.
Helping the needy.

As President Russell M. Nelson has taught: “Fasting helps your spirit to develop dominance over your physical appetites. Fasting also increases your access to heaven’s help, as it intensifies your prayers” (Oct. 2013 general conference [Ensign or Liahona, Nov. 2013, 107]).

In addition, the law of the fast also has the purpose of helping those in need (see Isaiah 58:3–11). Today, we are asked to skip two meals and give an offering of at least the value of those meals. Our generous fast offerings go directly to helping the poor and needy, and we are blessed as well.

As President Henry B. Eyring of the First Presidency has taught, “In [the Lord’s] Church we are invited to help Him as He cares for the poor in His way, and … He promises everlasting blessings will come from our helping Him” (“Is Not This the Fast That I Have Chosen?” Apr. 2015 general conference [Ensign or Liahona, May 2015, 25]).