Interestingly, genome-wide association studies in humans have revealed a robust association of single nucleotide polymorphisms (SNPs) with excess weight and obesity, not only in or near to the BDNF gene (for a review, see Xu and Xie, 2016) but also in intron 1 of the fat mass and obesity-associated protein (FTO) gene (Dina et al., 2007; Scuteri et al., 2007; Frayling et al., 2007; for a review, see Hess and Brüning, 2014). Here, BDNF is linked to obesity due to melanocortin 4 receptor deficiency.