INS and obesity due to melanocortin 4 receptor deficiency: This and the central role of DA signaling in attention, cognition and impulsivity [23–29], suggest impairments in central insulin signaling as a possible proximal cause of the reports of diabetes mellitus-associated deficits in behavioral self-regulation [30–33] and further, may explain the mixed findings with respect to obesity-associated deficits [34–47] (and see recent review by Bartholdy et al 2016 [48]).