LEP and obesity due to melanocortin 4 receptor deficiency: Further characterization of the complex relationship of reproductive function with energy metabolism may uncover the basis for inconsistencies such as the opposite effect of obesity on pubertal maturation in boys and girls (Wang, 2002; Burt Solorzano and McCartney, 2010; Walvoord, 2010), and the intriguing correlation of serum leptin with nocturnal but not with diurnal gonadotropin secretion in pubertal girls and adult women (Matkovic et al., 1997; Licinio et al., 1998).