Diabetes mellitus is known to be a serious chronic disease that requires great attention because it is the cancer that never dies and affects many people worldwide; its later complications are often numerous and frightening, and some of them may even affect their children as hereditary diseases. The relationship between lipid metabolism and insulin sensitivity in relation to diabetes is therefore even more important in this context. Insulin plays an important role as a key metabolic hormone in regulating glucose intake and maintaining lipid metabolic homeostasis. Insulin resistance interferes with the homeostasis of lipid metabolism while triggering related metabolic diseases such as type 2 diabetes. This review focuses on the relationship as well as interactions between lipid metabolism as well as insulin sensitivity and the specific factors affecting lipid metabolism and insulin sensitivity in terms of excess lipid accumulation, lipid deficiency, altered lipid composition, and specific lipid species. Finally, interventions based on the factors affecting lipid metabolism and insulin are proposed to improve metabolic health and reduce the risk of metabolic diseases such as diabetes.