CAT and obesity due to melanocortin 4 receptor deficiency: Exposure to obesity for a long time in a host system downregulates and depletes the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx); these enzymes being found to be significantly lowered compared with healthy persons which in turn lead to the development of obesity-related health problems [213].