Offspring from diabetic rats and mice have increased susceptibility to body weight dysregulation and obesity due to: increased expression of the orexigenic (NPY and AgRP) and decreased expression of the anorexigenic (α-MSH) peptides in the ARC (35, 30), leptin resistance in 10-day old pups, decreased fiber density of AgRP and α-MSH peptides, as well as in the PVN, and increased food intake and body weight (31). This evidence concerns the gene NPY and obesity due to melanocortin 4 receptor deficiency.