Authors suggested that individuals with obesity and high irisin levels also had a better prognosis, lipid metabolism regulation (considering the inhibition of adenosine triphosphate synthesis and consequently heat production), as well as a lower probability of complications related to insulin resistance, reducing serum insulin levels [23, 24, 34, 37, 45]. Here, FNDC5 is linked to obesity due to melanocortin 4 receptor deficiency.