Based on the previous study that growth and thyroid hormones play the main role in the growth of preschool children and that GH acts mainly through IGF-1 [37, 38], this study speculated from the perspective of hormones that the interaction of GH and IGF-1 might play the most significant role in accelerating skeletal maturation in preschool children with overweight/obesity. This evidence concerns the gene IGF1 and obesity due to melanocortin 4 receptor deficiency.