The hypothesis was based in two premises: (i) IL6 produced in response to exercise improves memory and cognition, at least in part, due to its neurogenic roles in the hippocampus [19, 23] and (ii) IL6 produced in response to exercise reduce obesity-associated hypothalamic inflammation restoring the control of food intake and energy expenditure [21]. This evidence concerns the gene IL6 and obesity due to melanocortin 4 receptor deficiency.