Under obesity conditions, excess free fatty acids (FFAs) decrease the lipid storage capability of adipose tissue, resulting in hypertrophic adipocytes and overproduction of adipokines and cytokines such as tumor necrosis factor (TNF), interferon-γ, interleukin (IL)-1β, IL-6 and IL-18 triggering systemic inflammation (5, 6). Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.