LEP and obesity due to melanocortin 4 receptor deficiency: Of the seven obesity/diabetes‐related hormones measured, leptin was the only factor that differed between Park2 KO and WT mice on both diets, where plasma levels were 65% and 94% less in RC‐ and HFD‐fed Park2 KO compared with WT mice, respectively (p < .05, p < .001; Table 1).