This research was done by Prof. Valter Longo at USC. I recently interviewed Valter and he talked in great detail about prolonged fasting and how it affects the clearance of damaged cells through autophagy, boosts stem cell production to replace the damaged cells and more. He also talks a great deal about the fasting mimicking diet and how it may affect disease risk and treatment. It is a really great podcast and I recommend to listen to it (or watch it).