Katherine Harmon, writing for Scientific American:
Most mice in the fasting groups were able to gain their weight back in five days or so. But humans, of course, are very different animals. Small fasting studies in cancer patients—some involving as long as 62 hours without food before treatment and 24 hours without food afterward—so far have produced only small side effects, Longo says, such as fatigue and headaches. And as Barcellos-Hoff notes, “I think humans would be much grouchier after two days without food.” But so far the method seems to be relatively well tolerated in small, carefully controlled studies. And “chemotherapy does make you feel really bad,” Barcellos-Hoff says. So fasting “is a lot less unpleasant than many of the things cancer patients are subjected to.”
Interesting approach!