INS and obesity due to melanocortin 4 receptor deficiency: In addition, considering that the two age groups consisted of the same percentage of participants with overweight–obesity and normal-weight participants, this difference in immune response could be attributed to the lower FGIR displayed by the older ones, probably due to the transient insulin sensitivity decrease during puberty, although the literature supports that in otherwise healthy adolescents, pubertal IR is accompanied by compensatory insulin secretion [43].