This finding occurred mainly due to the fact that the unadjusted leptin levels were lower in patients with fibromyalgia and overweight/obesity than in controls with overweight/obesity (14,715.00 ± 8,884.65 pg/mL versus 23,903.00 ± 9,788.74 pg/mL; p < 0.005). This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.