While we're on the subject of fasting, I have my own confession: I never much cared for it.
I am prone to what I assume are low-blood-sugar headaches, so growing up, fasting always had the association of blinding pain and nausea for me. As a teenager, I grew to like the buzz you could get from fasting; your knees shake a little and your arm trembles involuntarily. You feel wonderfully light-headed and dizzy (Mormons will do anything to get around the Word of Wisdom, won't they?). At any rate, while it was enjoyable and gave me the sense of inner physical strength, I can't say it was an overtly religious experience.
Then came my mission. On my first fast Sunday in the MTC, an Elder passed out in the food line and we had to carry him out. Diagnosis? Dehydration.
Fasting is all very well and so forth, but making missionaries fast is stupid. And making missionaries fast in warm climates is downright dangerous. Under a beating sun, walking and tracting while wearing a tie is not conducive to hydration. At least my mission in Argentina was not tropical; I don't know what the Elders in the Philippines and Central America do.
On my mission, I finally developed a system that worked for me. After returning to the apartment on Saturday night with my companion, I would drink a two-liter bottle of Coke. I was so full, I didn't even want to eat or drink anything in the next 24 hours. It wasn't quite the spirit of the law, I know, but it got me through the Sunday.