I decided after my mission in Spain that, at some point in my life, I wanted to go 48 hours without food. I figured that this was the closest that I could come to experiencing what so many others have experienced without dealing harm to my body. Lately, I've also been in a competition with "the landlord" to see who can lose the most weight in a four-month period. So, this weekend I designated Friday 4:30-Sunday 4:30 as my no-calorie time (Rachel won't let me call it a fast for such an unworthy purpose). A few observations:
The main inconvenience during the first 24 hours is the hunger and desire for food. The second 24 hours, the main culprit is lethardy and weakness. My desire for food did not increase (it might have even decreased a little bit). Additionally, the hunger pains increased only marginally.
The lethargy from hunger near the end of the 48 hours is similar to what you feel after a hard day's work on no sleep (my trip up King's Peak elicited a comparable feeling) only it's less soporific.
The second 24 hours, a set of weird (but minor) symptoms kick in. For me they included light headedness, irritible legs, and sensitive eardrums.
At the end of fast Sunday, the impulse to gorge is high, and afterwards a peaceful, content feeling comes over me as a lie sprawled out on a coach. Not so with the 48-hour fast. After gorging, the sudden rush of food in a stomach not used to it, while it feels good, comes with its own litany of symptoms. While it's better than not having food in the stomach, it comes with its own unique sense of uneasiness uncomfort.
Diminishing returns applies to crash weight loss. The first 24 hours I lost 5 lbs, and the second I lost 4 lbs. (and that was with cutting out water for the last 15 hours).
Overall, I'm glad that I had the experience, but I will never do it again.