Although ectopic over-production of adiponectin can reduce food intake in high fat fed rats and offset the development of diet-induced obesity (Shklyaev et al., 2003), food intake in adiponectin knockout mice is no different from that seen in wild-type littermates (Maeda et al., 2002). This evidence concerns the gene ADIPOQ and obesity due to melanocortin 4 receptor deficiency.