INS and obesity due to melanocortin 4 receptor deficiency: Human and animal studies also showed that maternal obesity or overnutrition during conception or lactation can modulate DNA methylation of different genes involved in energy metabolism, glucose homeostasis, insulin signaling and fat deposition, which support the role of DNA methylation in maternal obesity-induced risk of NAFLD, obesity, diabetes, and CKD (Table 1) [48,49,50,51,52,53].