In addition to increased FFA levels, other active metabolites are involved in obesity, such as ceramides, diacylglycerols, and acetyl-coA, which act by stimulating protein kinases, such as N-terminal c-Jun kinase (JNK), protein C-kinase (PKC), and nuclear factor-κ B (NFκB) inhibitor, which are responsible for impairing insulin sensitivity by increasing inhibitory phosphorylation [8,9]. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.