INS and type 2 diabetes mellitus: Several studies showed that brain mitochondrial dysfunction occurred in cases of HFD consumption, the genetically-induced obese-insulin resistant condition, and in cases of T2DM, indicated by the excessive production of mitochondrial ROS, mitochondrial membrane potential changes, and swollen mitochondria with evidence of unfolded cristae in mitochondria (6, 8, 11–16, 19, 28–31, 116).