Though adiponectin is produced by adipocytes, circulating adiponectin levels in the obese are lower than in the non-obese (the so-called adiponectin paradox) [32] and the increase in serum adiponectin is associated with weight loss (i.e., in patients with anorexia nervosa or in animal models of caloric restriction) [33,34]. This evidence concerns the gene ADIPOQ and anorexia nervosa.