Over the course of evolution, long periods of fasting were inevitable and species have developed coping mechanisms for better survival. At the moment, most of the western world has reached a point where nutrients are abundant and excessive, leading to accumulation of metabolic problems and a rise in chronic diseases in the second half of life. Existing concepts of life- and healthspan extension promote caloric restriction and fasting as potential methods to alleviate risks of chronic diseases, activating autophagy, and regeneration. The current article describes molecular and cellular mechanisms involved in the physiological effects of intermittent fasting (IF) and provides an integrated overview of existing experimental data and clinical trials. In multiple models, different modifications of IF show promising results, prolonging lifespan and improving surrogate healthspan markers. In humans IF promoted modest results in weight loss and had positive effects on insulin sensitivity, lipid profile, and inflammation. High quality evidence about the feasibility and long-term outcomes of IF in humans is still lacking. It remains unclear whether IF provides sustainable improvements. Further research is warranted to evaluate the optimal duration of IF, frequency of IF cycles and meal composition for the feeding intervals. The safety of IF is another major concern and so potential patient cohorts where IF might not be the best option must also be determined.

Intermittent fasting, Lifespan extension, Metabolism, Model organisms
Department of Biology

Lushchak, O. (Oleh), Strilbyska, O. (Olha), Piskovatska, V. (Veronika), Koliada, A. (Alexander), & Storey, K. (2019). Intermittent fasting. In Encyclopedia of Biomedical Gerontology (pp. 279–290). doi:10.1016/B978-0-12-801238-3.62133-5