Fasting means abstaining from some pleasure such as food, drink, sex, or television for a designated period of time. The Bible gives many examples of people who fasted for a specific time and purpose.
According to Matthew 6:16-18, one should pray as well as fast.
The "acceptable fast" is discussed in the biblical Book of Isaiah, chapter 58:6–7. In this chapter, the nation of Israel is rebuked for their fasting because they weren't doing it for the right reasons. The acceptable fast is not merely abstinence from food or water, but a decision to fully obey God's commands to care for the poor and oppressed.
Fasting is not done to lose weight even though that might happen during the fasting period. Fasting is usually done for spiritual purposes. If you have a specific concern, fasting will help you hear from God.
Fasting, like the other disciplines, requires practice. If you are not in the habit of fasting, start off for a short period of time. When you fast for longer periods, God will let you know when it is time for the fast to end.
Fasting helps to clear your body of toxins, rid your mind of negative thoughts, and makes your spirit connect with the Spirit of God.
Try giving up a pleasure to let God know you are serious about what you are requesting.