Hey Scott,
I can't speak for others but my experience is as follows. Fasting starts with the belief that I am a created being and one that is a temporary guest in the Creator's dominion. Therefore, nothing in this world belongs to me. When my Host asks me to refrain from doing somethings, I respect His wishes.
The other aspect is why I should fast and why it is good for me. Fasting highlights one of the most fundamental human needs, food. This desire of hunger is given to us and when it is not satisfied, you become really needy. From this state of hunger, I learn to realize how many other needs I have and the One whom is responsible for satisfying my needs.
Historically, the Qur'an was revealed during Ramadan (and then over 23 years). Personally, it wasn't revealed because Ramadan was holy. Take it into my context now, the Qur'an MAY be revealed to me when I am ready to realize the wisdom in its message. Therefore, what makes Ramadan holy is the raised level of awareness of the Creator's presence. If I am not ready, the message will never get to me.
I believe every religion if not most, subscribe fasting as a means to discover oneself. Even if you are an atheist, there are many idioms like "You truly discover your good friends in times of trouble" or "Only thru adversity, a true champion arises". Fasting is consistent with the natural order of the universe.
So, if I do not start from a consciousness of belief, fasting is just dieting.