BDNF and obesity due to melanocortin 4 receptor deficiency: The purpose of this study was to examine whether carriers of the BDNF Val66Met polymorphism Met-allele (Val/Met -G/A alleles or Met/Met-A/A alleles) differed from carriers of the homozygous Val/Val (G/G) alleles on anthropometrics, cardiometabolic risk factors, and energy intake in a sample of adolescents living with overweight and obesity.