Obesity can cause a chronic low-grade inflammatory state with high levels of cytokines such as TNF-α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), and IL-6, which in part contributes to the pathogenesis of insulin resistance, promoting a reduction in glucose uptake in insulin-dependent tissues, which increases blood glucose levels, β-cell dysfunction in pancreas and results in endocrine dysfunction of adipose tissue. Here, CCL2 is linked to obesity due to melanocortin 4 receptor deficiency.