MC4R and Obesity: Not surprisingly, the latest metaanalysis of genome-wide association studies of obesity and the metabolic syndrome (not IR) found polymorphisms in genes relevant for food intake such as FTO (fat mass and obesity related), MC4R (melanocortin receptor type 4), POMC (proopiomelanocortin, the precursor of melanocortin), and genes relevant for fat storage such as the insulin-stimulating GIPR (gastric inhibitory polypeptide receptor) [93].