Both a negative energy balance caused by long-term food restriction [2] and positive energy balance induced by dietary obesity [3] can lead to decreased serum testosterone levels, spermatogenesis, and sexual dysfunction in men, often accompanied by a decrease in serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Here, PLOD1 is linked to obesity due to melanocortin 4 receptor deficiency.