Increased circulating pro-inflammatory cytokines and adipokines (e.g. TNF-α, leptin, resistin, plasminogen activator inhibitor-1, CRP, IL-1β and IL-6) contribute to systemic inflammation in obesity but are also established predictors of cognitive impairment (Kiliaan et al., 2014). Here, IL6 is linked to obesity due to melanocortin 4 receptor deficiency.