Role of Ketogenic Diets and Intermittent Fasting in Neurologic Diseases, Cancers, and Obesity: A Systematic Review of Human Studies

Ketogenic diet (KD) and intermittent fasting (IF) are non-pharmacologic nutritional therapies with modest side effects such gastrointestinal discomfort, dyslipidemia, and hypomagnesemia for various medical conditions. KD and IF may help with weight loss, diabetes, cardiovascular disease, polycystic ovarian syndrome, cancer, and chronic neurological illnesses. We studied KD and IF's impact on cancer, obesity, and neurodegenerative illnesses. We advised evidence -based KD and IF safety. KD is hard to maintain despite benefits. Thus, occasional KD adoption may help newly diagnosed overweight or obese type 2 diabetics lose weight and control blood glucose and lipids. KD is a high -fat, low -carbohydrate diet with 4:1 or 3:1 fat to carbohydrates and protein, thus peripheral tissues and the brain need fatty acids for energy. Most fasting energy comes from ketones. KD has been reliably used to treat refractory epilepsy since the 1920s. KD prevents epilepsy, stroke, severe brain injury, Alzheimer's, and other neurological illnesses. KD has been used to treat obesity since the 1960s. Combining chemotherapy and radiation with KD may increase tumor cell sensitivity. Thus, KD can be used to treat obesity, cancer, and chronic neurological disease without medicine or side effects. As an adjuvant therapy, KD may offer new neuroprotection and neuroscience treatments. Antioxidant defense and inflammation reduction may alleviate Alzheimer's and Parkinson's risk. By targeting cancer cell metabolism, KD and IF may be used to treat cancer. Radiation and chemotherapy may be intensified when used in conjunction with KD. In aggressive brain cancer glioblastoma, KD is most promising. Ketosis suppresses hunger, aiding weight loss in overweight or obese patients. Among type 2 diabetes patients, it helps to manage blood glucose and cholesterol, but long-term adherence is difficult. If paired with exercise, IF may be more effective than calorie restriction for weight loss. Further prospective human trials are needed to assess KD and IF's therapeutic efficacy and safety.