INS and obesity due to melanocortin 4 receptor deficiency: The carbohydrate-insulin model of obesity postulates that diets high in carbohydrate result in elevated insulin secretion thereby trapping fat inside adipocytes, decreasing the availability of circulating fuels, and generating a state of “internal starvation” in non-adipose tissues that signals to the brain to suppress energy expenditure and increase hunger [1, 2].