The melanocortin-4 receptor (MC4R) is important for control of food intake, and loss of this receptor elicits obesity in laboratory animals (Chagnon et al. 1997; Huszar et al. 1997; Yeo et al. 1998; Mul et al. 2012). This evidence concerns the gene MC4R and obesity due to melanocortin 4 receptor deficiency.