A study of 65 men with obesity offered laparoscopic sleeve gastrectomy and showed that patients with obesity without AN (N = 20) had less severe metabolic parameters at baseline compared with patients with obesity and AN (N = 45); within one year since surgery, AN score was significantly reduced, and was correlated with significant improvements in BMI, serum insulin, HOMA-IR, inflammatory status, and total testosterone [85]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.