INS and diabetes mellitus: • GTT and GSIS were impaired in maternal diabetes-exposed offspring at adulthood (24). • Insulin secretion, glucose utilization and oxidation were reduced in islets of O-GDM at 15-week-old (25). GSIS worsened when offspring was fed HFHS diet (26). • Insulin and beta cell mass were increased in diabetic fetuses (27). • Fetal pancreas of GDM identified 219 biochemicals with significant changes (28).