INS and obesity due to melanocortin 4 receptor deficiency: A meta-analysis carried out on 1577 patients with obesity randomized in the low-fat diet (n = 787) and VLCKD (n = 790) (females were the majority in almost all the studies included in the meta-analysis) has shown significant decrease in body-weight and blood-pressure in subjects assigned to VLCKD than low-fat diet, but no significant difference was found for glucose, insulin, and HbA1c levels [18].