The definitions of the MHO phenotype in youth with obesity used in previous studies were most commonly based on: (a) absence of cardiometabolic risk factors (16, 25–27), (b) presence of ≤1 cardiometabolic risk factor (24, 27, 28), (c) presence of ≤2 cardiometabolic risk factors (29), (d) other criteria such as preserved insulin sensitivity or a combination of the above criteria (14, 30, 31). This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.