As a result of maternal overnutrition, it is shown that the increased placental transfer of nutrients to the developing fetus in obese mothers and mothers who gain excess weight during pregnancy, may subsequently affect fetal and neonatal body composition and metabolism; particularly including leptin expression increment in subcutaneous and visceral fat mass, leptin resistance and childhood obesity in postnatal life (Ay et al., 2009; Freeman, 2010; Muhlhausler and Ong, 2011; Ong et al., 2012; Kabaran, 2014; Montalvo-Martínez et al., 2018). This evidence concerns the gene LEP and overnutrition.