Obesity is associated with decreased plasma adiponectin concentrations and a chronic low-grade inflammation characterized by increased adipose tissue expression of pro-inflammatory chemokines and cytokines such as MCP-1 [25] and TNF-α [26], as well as infiltration of M1 (pro-inflammatory) macrophages [27], [28]. Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.