BACKGROUND AND OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is a reversible disease that is mainly a result of high-fat diets in humans. This study aims to induce fatty liver by formulating a high-fat diet in rats to provide a simple and accessible model for investigating various aspects of this disease.

METHODS: This experimental study was conducted using 18 male Wistar rats weighing 180±20 g, randomly divided into two groups (n=9). One group was fed with standard diet whereas the other group was fed with high-fat diet (based on animal fat and cholesterol) for 10 weeks. After this period, variables of weight change, glucose, liver enzymes and serum lipid profile were measured and histopathological changes in the liver tissue were investigated and compared between the two groups.

FINDINGS: At the end of the tenth week, the mean triglycerides and serum cholesterol were 53.71±9.1 mg/dl and 56.42±5.7 mg/dl, respectively in control group, revealing a significant difference compared with the high-fat group (90.85±13.4 mg/dl and 94.28±9.9 mg/dl, respectively) (p<0.05). The level of aspartate aminotransferase increased from 89.85±12.7 IU/L in the control group to 147.84±17.8 IU/L in the high-fat group. Moreover, the level of alanine aminotransferase increased from 46.28±7.2 IU/L in the control group to 86.85±9.2 IU/L in the high-fat group, which was statically significant (p<0.01). In addition, histopathological changes in liver including fat vacuole and hepatocyte swelling were observed in the high-fat group.

CONCLUSION: According to the results of this study, a formulated high-fat diet can well induce a non-alcoholic fatty liver in rats.