Bmal1 and AMPK are the key regulators for metabolic fitness by regulating the hepatic mitochondrial function.(45) In addition, certain nutrients increase Per2 expression through the insulin secretion.(33,34) Taken together findings in this study and these previous reports suggest that CLPr acts as a clock-regulator to prevent and/or ameliorate metabolic disorders when administration of it at the suitable timing. This evidence concerns the gene PER2 and metabolic disease.