|"Your light will break forth like the dawn"|
Personally, I've been challenged by meditating on Isaiah 58. God speaks about the fast HE WANTS. "This is not the fast that I have chosen: Loose the bonds of wickedness, undo heavy burdens, share your bread with the hungry. Bring to your house the poor who are cast out. When you see the naked cover him. Do not hide yourself or forget your own flesh [family]. Then your light will break forth like the morning and your healing shall spring forth speedily."
Who doesn't want to have healing? Who doesn't want to be well? Healing in body, soul and spirit is associated with God's fast - caring for those in need.
The reason for fasting is often given to "draw near to God", or "to feel repentance for sins". God says that the reason for fasting is two-fold. First, withdrawing from our own comfort zone to help those in need releases spiritual energy - like the sun as it brings forth another day.
Secondly, our own health, about which we are concerned when we begin to fast, will result in healing as we come into harmony with God's purposes for the poor.
Colossians 1:11 We pray that you may be invigorated and strengthened with all power according to the might of his glory, to exercise every kind of endurance and patience [perseverance and forbearance] with joy. (Amplified)