KCNK2 and obesity due to melanocortin 4 receptor deficiency: Next, to evaluate the systemic effects of TREK-1 on the development of obesity, we subjected wild-type (WT) and TREK-1 KO mice to either a normal chow diet (NCD) or a high-fat diet (HFD) from 8 to 20 weeks of age (Fig. 7A).