CAT and obesity due to melanocortin 4 receptor deficiency: MDA is the main product of lipid peroxide degradation, which not only prevents mitochondrial respiratory chain electron transfer but also promotes inflammatory response, thus promoting liver antioxidant enzyme activity (SOD, CAT, and GSH-Px) and inhibiting peroxidation products MDA content and antioxidative stress can promote lipid metabolism and prevent NAFLD caused by obesity [25, 47].