The effects of intermittent fasting regimens in middle-age and older adults: Current state of evidence

Exp Gerontol. 2021 Dec:156:111617. doi: 10.1016/j.exger.2021.111617. Epub 2021 Oct 30.


Aging is associated with a host of biological changes that contribute to a progressive decline in cognitive and physical function, ultimately leading to a loss of independence and an increased risk of mortality. The unprecedented growth of the aging population has thus created an urgent need for interventions that can preserve older adults' capacity to live independently and to function well. To date, there is no conclusive evidence supporting the efficacy of an intervention to prevent or reverse physical disability in older persons at risk of functional decline. A growing body of evidence indicates that prolonged fasting periods and different types of intermittent fasting regimens can have positive effects on anthropometric and metabolic health parameters in middle-aged adults similar to that of calorie restriction. For this reason, there is increasing scientific interest in further exploring the biological and metabolic effects of intermittent fasting approaches, as well as the feasibility and safety of popular types of intermittent fasting regimens in older adults. Thus, the purpose of the present review is to describe the state of evidence of different types of intermittent fasting regimes, specifically time-restricted eating and 5:2 intermittent fasting, in the growing population of middle-aged and older adults. A small, but growing body of evidence indicates both time restricted eating (TRE) and 5:2 intermittent fasting approaches can produce modest weight loss; however, only the 5:2 approach produced clinically meaningful weight losses. Reductions in blood pressure were observed for both TRE and 5:2 fasting approaches, but the effects were not consistent across studies. The majority of studies to date, in middle-age and older adults, however, have been of short duration in small study samples. Future clinical trials with larger populations and longer intervention durations are required to better understand the risks versus benefits of different types of intermittent fasting regimens in middle-age and older individuals.

Keywords: Aging; Diet; Metabolic Switch; Obesity; Time Restricted Eating.

Publication types

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

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging
  • Caloric Restriction*
  • Fasting* / physiology
  • Humans
  • Middle Aged
  • Time Factors
  • Weight Loss