SCD and obesity due to melanocortin 4 receptor deficiency: Previous studies reported that Scd1 global knockout (KO) mice showed improved insulin sensitivity, higher-energy metabolism, and more resistant to diet-induced obesity by the activation of lipid oxidation in addition to the reduction of triglyceride synthesis and storage (Ntambi et al., 2002; Miyazaki et al., 2007; Miyazaki et al., 2009).