We found that liver steatosis could be induced in zebrafish larvae at 5 dpf, with only one day of HFD that increased oil red o staining, liver size with respect to whole body, triglyceride content, and mRNA level of apolipoprotein A-II (apoa2 and cyp2y3 gene—homologous of the human CYP2E1 gene—in comparison to a standard diet (SD) [27]. The gene discussed is APOA2; the disease is fatty liver disease.