Fasting is generally received with a sideways glance of disapproval or a beeline for the ice cream cooler. We rarely seek out the uncomfortable and saying no to food is on the list of taboos.

Ten years ago I fasted every Tuesday for a year. Somewhere in there, was a 5-day fast. Tonight I conclude a 72-hour water-only fast (I did cheat at hour 62, with two tsp of coconut oil). The weekly fasts were for spiritual reasons and the last few days have been primarily to understand the physical implications for me.

Compounding scientific studies conclude...