One possible explanation is the impairment of thyroid hormones capacity to induce thermogenesis in obesity, due to reduced expression of thyroid hormone receptors, D2 and D3 enzymes, β2 and β3 adrenergic receptors, and UCP-2 in the adipose tissue (especially the visceral) of these individuals (6). This evidence concerns the gene TG and obesity due to melanocortin 4 receptor deficiency.