DRD2 and obesity due to melanocortin 4 receptor deficiency: According to our results and findings in the literature, the increase in dopaminergic transmission that may anticipate binge-eating behavior induced by intermittent exposure to sucrose (Rada et al., 2005; Bello and Hajnal, 2010), as well as the hyposensitivity of the reward system (due to the lower dopaminergic activity in the circuit of reward) in obesity (Geiger et al., 2008, 2009; Leigh and Morris, 2018) converge in the alteration of the dopaminergic transmission mediated by dopamine D2 receptors (Zhang et al., 2007; Johnson and Kenny, 2010; Davis et al., 2012, 2013).