Bioactive mediators derived from ω-3 PUFAs, SPMs, including the resolvins E1 (RvE1) and D1 (RvD1), protectin D1 (PD1) and maresin 1 (MaR1) were found to limit obesity associated inflammation, switch macrophage polarization to M2 and improve insulin sensitivity in type 2 diabetes26,30–33. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.