PPARA and obesity due to melanocortin 4 receptor deficiency: For this, we used High Fat Diet (HFD) feeding as a model of obesity in C57BL/6 J male Wild-Type mice (WT), in whole-body Pparα- deficient mice (Pparα−/−) and in mice lacking Pparα only in hepatocytes (Pparαhep−/−).