Diet is a convenient and quick treatment. The high-fat low-carb ketogenic diet has been used to treat epilepsy for nearly a century. Although ketogenic diet has been neglected by the development of antiepileptic drugs the related research on ketogenic diet has shown an explosive growth in recent years and it has been found that ketogenic diet plays a positive role in mental and psychological diseases chronic diseases and even tumors. However it can also cause LDL levels to rise making many doctors hesitant. This paper aims to introduce the effects of ketogenic diet on human metabolism from the perspective of glycolipid metabolism and intestinal flora summarize its positive effects in Alzheimer's disease depression diabetes obesity and even tumors and highlight the potential side effects of ketogenic diet providing new ideas for clarifying the potential application value of dietary intervention strategies.