Most animals alternate periods of feeding with periods of fasting often coinciding with sleep. Upon >24 hr of fasting, humans, rodents, and other mammals enter alternative metabolic phases, which rely less on glucose and more on ketone body-like carbon sources.
Both intermittent and periodic fasting result in beneﬁts ranging from the prevention to the enhanced treatment of diseases. Similarly, time-restricted feeding (TRF), in which food consumption is restricted to certain hours of the day, allows the daily fasting period to last >12 hr, thus imparting pleiotropic beneﬁts.
Understanding the mechanistic link between nutrients and the fasting beneﬁts is leading to the identiﬁcation of fasting-mimicking diets (FMDs) that achieve changes similar to those caused by fasting. Given the pleiotropic and sustained beneﬁts of TRF and FMDs, both basic science and translational research are warranted to develop fasting-associated interven-tions into feasible, effective, and inexpensive treatments with the potential to improve healthspan
Valter D. Longo and Satchidananda Panda, Perspective - Cell Metabolism, 23, June 14, 2016