Alternatively, since lean mass in adults with obesity is characterized by greater myosteatosis (Miljkovic & Zmuda, 2010) and skeletal muscle extracellular matrix (Sachs et al., 2019), myostatin may mediate the relationship between greater myosteatosis and/or skeletal muscle extracellular matrix and lower insulin sensitivity in adults with obesity. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.