From a glucose metabolism standpoint, chronic oxytocin administration in animal models of diet-induced obesity and diabetes has resulted in improvement of glucose tolerance and insulin resistance in the majority of studies [81,98,103,116], with one study showing worsening of basal glycemia, glucose tolerance, and insulin sensitivity in extremely obese and diabetic (ob/ob) mice [104]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.