EPA supplementation was found to alleviate hyperglycemia of InsrP1195L/+ mice fed HFD (InsrP1195L/+/HFD mice), which was accompanied by amelioration of increased gluconeogenesis and impaired insulin signaling, as assessed by glucose-6-phosphatase (G6pc) expression on refeeding and insulin-induced phosphorylation of Akt in the liver, respectively. The gene discussed is INS; the disease is Hyperglycemia.