After reading Taleb’s arguments for improving our life and its passionate defense of random, irregular fasting, I was curious if there were any controlled studies on the health effects of fasting in humans.
There is not much. If you go to Wikipedia fasting entry, there appear to be only anecdotal evidence, most of it showing benefits. This article, for instance, talks about the weight losing and cholesterol improving effects of intermittent fasting:
Or, for example, look at this other article:
that begins criticizing the fasting approach but ends up defending it.
We have no empirical evidence on one side or the other and we have the fact that most humans have forcibly fasted for most of human history and that most religions include fasting as a ritual of purification.