Importantly, while lower POMC expression in the ARC is often viewed as a correlate for adult obesity (35, 36), several reports show that prolonged exposure to obesogenic diets or to early life obesogens lead to increased POMC expression in the ARC, arguing that overexpression of POMC in the ARC occurs as part of an allostatic process that is engaged to maintain homeostasis (37, 38). This evidence concerns the gene POMC and obesity due to melanocortin 4 receptor deficiency.