INS and type 2 diabetes mellitus: Additionally, rats given high-fat diets and low-dose streptozotocin are shown to have impaired insulin secretion, glucose intolerance, insulin resistance, and obesity, making them suitable as an alternate animal model for type 2 diabetes; hence, NA/STZ accompanied with HFD could serve as an appropriate animal model for type 2 diabetes (Tahara et al., 2011).