A proposed mechanism of the association between AMPD1 genotype and obesity-related traits could be the impact of AMPD activity on the AMP-activated protein kinase (AMPK) activity, a key energy-sensing and signaling network that phosphorylates many proteins affected in cellular energy balance (e.g., by stimulating cellular glucose uptake) [30,31]. This evidence concerns the gene AMPD1 and obesity due to melanocortin 4 receptor deficiency.