Intermittent fasting (IF) involves periodic periods of fasting with normal eating cycles, and has been shown to improve health and prevent diseases in animals and humans. IF includes methods such as alternate day fasting (ADF), time-restricted feeding (TRF), and periodic fasting (PF). Studies in animals and humans have demonstrated that IF can reduce body weight, improve glucose metabolism, lower blood pressure, and reduce inflammation. IF also enhances mitochondrial function, DNA repair, and autophagy, which are crucial for cellular health. In humans, IF has been shown to improve weight loss, reduce insulin resistance, and lower cardiovascular risk factors. IF may also protect against age-related diseases such as diabetes, cardiovascular disease, cancer, and neurological disorders like Alzheimer's and Parkinson's. However, the long-term efficacy and safety of IF in humans require further study, particularly in comparison to continuous energy restriction (CER). While IF shows promise in improving health and disease resistance, more research is needed to determine the optimal regimen and its effects on different populations.Intermittent fasting (IF) involves periodic periods of fasting with normal eating cycles, and has been shown to improve health and prevent diseases in animals and humans. IF includes methods such as alternate day fasting (ADF), time-restricted feeding (TRF), and periodic fasting (PF). Studies in animals and humans have demonstrated that IF can reduce body weight, improve glucose metabolism, lower blood pressure, and reduce inflammation. IF also enhances mitochondrial function, DNA repair, and autophagy, which are crucial for cellular health. In humans, IF has been shown to improve weight loss, reduce insulin resistance, and lower cardiovascular risk factors. IF may also protect against age-related diseases such as diabetes, cardiovascular disease, cancer, and neurological disorders like Alzheimer's and Parkinson's. However, the long-term efficacy and safety of IF in humans require further study, particularly in comparison to continuous energy restriction (CER). While IF shows promise in improving health and disease resistance, more research is needed to determine the optimal regimen and its effects on different populations.