Other studies have also proposed that both ASF and AVF play a role in metabolic risk [10] but largely the metabolic risk of obesity has been linked mainly to AVF because it is directly involved in the delivery of free fatty acids as well as inflammatory proteins such as interleukin-6 (IL-6), to the liver via the portal circulation [16]. Here, IL6 is linked to obesity due to melanocortin 4 receptor deficiency.