Fasting is often accompanied by Prayer to establish a higher dedication to God and bring breakthrough. It is mentioned throughout the Bible as a way of focusing and becoming in tune with the voice of God. Many of the Priests and Prophets do/did fast. By Fasting, we as Christians show that we have control over our sinful and carnal fleshy and worldly desires, and it puts us in-tune with God. As Jesus said to satan, it is written in the scriptures, that we should not live by bread alone, but every word that proceeds out of the mouth of God. Digest the Word of God, it is healthy and nutritious for the soul.
You should consult a doctor before you fast, to make sure it will not have any adverse effects. There are a couple of variants of Fasting. Intermittent fasting and juice fasting are probably the best to start of with if you are new to fasting. With intermittent fasting you simply fast (no food but water) sixteen hours a day, and eat three meals (breakfast, lunch and dinner) between 10AM and 6PM. With juice fasting, you simply drink juice for two to three days, and slowly re-introduce solids after the fasting period.
As it is written in the Word of God, in the New Testament, that there was a demon-possessed man and Jesus’s disciples could not get the demon to come out of him. The disciples said to Jesus, we tried to heal him, but Jesus remarks that the demon will only come out of the man with prayer and fasting. Doesn’t that show you the power of Prayer and Fasting? Jesus also mentions that we should fast without anybody knowing but God, as it is mentioned we should not wear sackcloth and ashes, and not have a countenance that lets people know we are fasting, to get glory from man, but we should fast to bring glory to God.