Intermittent fasting in health and disease

ContextIntermittent fasting, a new-age dietary concept derived from an age-old tradition, involves repetitive cycles of fasting/calorie restriction and eating.ObjectiveWe aim to take a deep dive into the biological responses to intermittent fasting, delineate the disease-modifying and cognitive effects of intermittent fasting, and also shed light on the possible side effects.MethodsNumerous in vitro and in vivo studies were reviewed, followed by an in-depth analysis, and compilation of their implications in health and disease.ResultsIntermittent fasting improves the body's stress tolerance, which is further amplified with exercise. It impacts various pathological conditions like cancer, obesity, diabetes, cardiovascular disease, and neurodegenerative diseases.ConclusionDuring dietary restriction, the human body experiences a metabolic switch due to the depletion of liver glycogen, which promotes a shift towards utilising fatty acids and ketones in the system, thereby significantly impacting adiposity, ageing and the immune response to various diseases. Intermittent fasting (IF) comprises repetitive fasting and feeding cycles.There are many variations of IF schedules.Individuals practicing an appropriate IF pattern reap numerous health benefits.The possible side effects should be considered before commencing a new IF regimen.