INS and fatty liver disease: Similar to the previous reports that short-term HFD feeding, e.g., for 3–4 days, is sufficient to induce liver steatosis and impair glucose tolerance and hepatic insulin sensitivity (Lee et al., 2011; Ji et al., 2012; Wiedemann et al., 2013; Chang et al., 2015), our data of hepatic H&E staining showed that a small amount of fat vacuoles accumulated in the liver of mice fed a HFD (Figure 2A), hepatic Oil red O staining and hepatic TG levels showed that HFD feeding induced fat deposition in the liver (Figures 2B,C).