TNF-α. It is a proinflammatory cytokine that exerts numerous effects in adipose tissue including lipid metabolism and insulin signaling whose circulating levels are increased with obesity and decreased with weight loss. An increase in TNF-α promotes the secretion of other proinflammatory cytokines IL-6 and TNF-α, and reduces anti-inflammatory cytokines like adiponectin. Evidence suggests that TNF-α induces adipocytes apoptosis and promotes insulin resistance by the inhibition of the insulin receptor substrate 1 signaling pathway.