Abstract

Increasedlongevity and improved health can be achieved in mammals by two feedingregimens, caloric restriction (CR), which limits the amount of dailycalorie intake, and intermittent fasting (IF), which allows the food to beavailablead libitum every other day. The precise mechanismsmediating these beneficial effects are still unresolved. Resetting the circadian clock is anotherintervention that can lead to increased life span and well being, whileclock disruption is associated with aging and morbidity. Currently, alarge body of evidence links circadian rhythms with metabolism and feedingregimens. In particular, CR, and possibly also IF,can entrain the master clocklocated in the suprachiasmatic nuclei (SCN) of the brain hypothalamus.These findings raise the hypothesis that thebeneficial effects exerted by these feeding regimens could be mediated, atleast in part, through resetting of the circadian clock, thusleading to synchrony in metabolism and physiology. This hypothesis is reinforced by a transgenic mousemodel showing spontaneously reduced eating alongside robust circadianrhythms and increased life span. This review will summarize recent findingsconcerning the relationships between feedingregimens, circadian rhythms, and metabolism with implications for ageingattenuation and life span extension.