It is the first report of the proposed weight loss mechanism of SIL CH NPs, thereby providing information about the anti-hyperlipidemic and antihyperglycemic effects of silymarin-loaded chitosan nanoparticles, a natural food with proper effects against metabolic disorders in case of hyperlipidemia that may lead to obesity and up-regulation of brain NPY. The gene discussed is NPY; the disease is Other metabolic disease.