Obesity is accompanied by increased visceral adipose tissue, which leads to the induction of several pro-inflammatory cytokines such as tumor necrosis factor-α (TNF α), IL-6, monocyte chemoattractant protein 1, and other chemokine ligands, all of which lead to monocyte recruitment and macrophage activation. Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.