for me anyway, fasting is much more than abstaining from eating for a day. as in the manner of Isaiah 53:3-10; but of course the rest of the chapter God makes known the results of true fasting. Again, for me, to fast is to "go without"; you may say, Go without what? namely our selfish desires, that we may esteem others needs: it may be fasting without your hand held device; or without other typical distractions that make up your daily things for self, apart from necessities: go without such things that represent conformity to this world, and the course of this world.
As for the Islam fast, for me it is not a fast, but merely changing the time in which to eat, and nothing more: for a true fast from eating would be from the time we wake up in the morning until the next day when we awaken; but to merely change the time in which we eat from day to night is of none effect concerning any sacrifice.
As for ceremonies, and rituals, and formalism; they cannot take away sin! but only repentance.