After analyzing all the differentially expressed genes, two classical KEGG pathways were found to be related to obesity, namely the PPAR-signaling pathway and energy metabolism, involving genes Fabp1–5, Lpl, Gyk, Qqp7, Pparg, Rxrg, Acsl1, Acsl4, Acsl6, Cpt1c, Car1–4, Ca5b, Car8, Car12–14, Cps1, Ndufa4l2, Cox6b2, Atp6v1g2, Ndufa4l2 and Cox4i2. Here, COX4I2 is linked to obesity due to melanocortin 4 receptor deficiency.