Intermittent fasting: from calories to time restriction

Geroscience. 2021 Jun;43(3):1083-1092. doi: 10.1007/s11357-021-00335-z. Epub 2021 Mar 9.


The global human population has recently experienced an increase in life expectancy with a mounting concern about the steady rise in the incidence of age-associated chronic diseases and socio-economic burden. Calorie restriction (CR), the reduction of energy intake without malnutrition, is a dietary manipulation that can increase health and longevity in most model organisms. However, the practice of CR in day-to-day life is a challenging long-term goal for human intervention. Recently, daily fasting length and periodicity have emerged as potential drivers behind CR's beneficial health effects. Numerous strategies and eating patterns have been successfully developed to recapitulate many of CR's benefits without its austerity. These novel feeding protocols range from shortened meal timing designed to interact with our circadian system (e.g., daily time-restricted feeding) to more extended fasting regimens known as intermittent fasting. Here, we provide a glimpse of the current status of knowledge on different strategies to reap the benefits of CR on metabolic health in murine models and in humans, without the rigor of continuous reduction in caloric intake as presented at the USU State of the Science Symposium.

Keywords: Calorie restriction; Calories; Fasting; Intermittent Fasting; Time Restricted Feeding.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Review

MeSH terms

  • Animals
  • Caloric Restriction
  • Diet
  • Energy Intake*
  • Fasting*
  • Feeding Behavior
  • Humans
  • Mice