Open Access Maced J Med Sci. 2022 Apr 30; 10(A):709-714. 709 Scientifc Foundation SPIROSKI, Skopje, Republic of Macedonia Open Access Macedonian Journal of Medical Sciences. 2022 Apr 30; 10(A):709-714. https://doi.org/10.3889/oamjms.2022.9383 eISSN: 1857-9655 Category: A - Basic Sciences Section: Biochemistry The Efects of High Fat Diet on the Liver of the White Rat Model Obesity Rusdiana Rusdiana 1 * , Siti Syarifah 2 , Yunita Sari Pane 2 , Sry Suryani Widjaja 1 , Dwi Rita Anggraini 3 1 Department of Biochemistry, Medical Faculty, Universitas Sumatera Utara, Medan, Indonesia; 2 Department of Pharmacology, Medical Faculty, Universitas Sumatera Utara, Medan, Indonesia; 3 Department of Anatomy, Medical Faculty, Universitas Sumatera Utara, Medan, Indonesia Abstract BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease with the manifestation of over-accumulation of fat in the liver. AIM: The purpose of this study was to assess the degree of occurrence of steatosis in rats induced by a standard diet, a high-fat diet, and a modifed high-fat diet. METHODS: This study used 18 white rats of the Wistar strain, divided into three groups, and fed for 9 weeks. Before feeding, all rats were measured their body weight, abdominal circumference, and body length. We measured body weight every week, while body length and waist circumference were measured every 2 weeks. After 9 weeks of diet, all rats were subjected to injection of Ketamine and examined for metabolic markers and histopathological examination of liver organs. RESULT: There was an increase in body weight of rats in the three groups with the average percentage increase in body weight in the three groups of rats before and after being fed a diet for 9 weeks found in Group 1 29.19% 1 (187−264.40 g), Group 2 by 19.12% (219.33−275 g), and Group 3 24.53% (213.33−275 g). Steatosis in Group 1 was 57.50% of hepatocytes containing macrovesicular fat droplets and called Grade 2 (moderate). In contrast, with a high-fat diet, steatosis occurred around 93.33%−95% of hepatocytes containing macrovesicular fat droplets and called steatosis Grade 3 (severe). CONCLUSION: The percentage of hepatocytes that had steatosis in obese rats induced by a high-fat diet was more signifcant than in obese models induced by a standard diet. Edited by: Slavica Hristomanova-Mitkovska Citation: Rusdiana R, Syarifah S, Pane YS, Widjaja SS, Anggraini DR. The Efects of High Fat Diet on the Liver of the White Rat Model Obesity. Open Access Maced J Med Sci. 2022 Apr 30; 10(A):709-714. https://doi.org/10.3889/oamjms.2022.9383 Keywords: Standard diet; High fat diet; Rat galur wistar; Steatosis *Correspondence: Rusdiana Rusdiana, Department of Biochemistry, Medical Faculty, Universitas Sumatera Utara, Jl. dr. Mansur Kampus USU Medan 20155, Indonesia. E-mail: rusdiana@usu.ac.id Received: 15-Mar-2022 Revised: 30-Mar-2022 Accepted: 20-Apr-2022 Copyright: © 2022 Rusdiana Rusdiana, Siti Syarifah, Yunita Sari Pane, Sry Suryani Widjaja, Dwi Rita Anggraini Funding: This research was supported by the Ministry of Research and Technology and the Higher Education Republic, Indonesia through the TALENTA USU grant (No: 347/UN5.2.3.1/PPM/SPP-TALENTA USU/2021) Competing Interests: The authors have declared that no competing interests exist Open Access: This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial 4.0 International License (CC BY-NC 4.0) Introduction Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease associated with metabolic disorders, such as type 2 diabetes mellitus, hypertension, dyslipidemia, and obesity [1], [2]. NAFLD exists on a spectrum from simple steatosis to steatohepatitis, characterized by steatosis, lobular infammation, hepatocellular swelling, and liver injury resulting in necroinfammation with fbrosis [3], [4]. Several factors include the occurrence of steatosis, such as diet and lifestyle [5]. Thus, briefy, lipid accumulation leading to the fatty liver may be mediated by several mechanisms: Increased free fatty acids (FFA) from exacerbation of lipolysis or intake of high-fat content, decreased FFA oxidation, increased de novo hepatic lipogenesis, and decreased secretion of very low-density lipoprotein (VFA and VLDL) and triglycerides in the liver [6]. Diet plays a crucial role in developing the nonalcoholic fatty liver disease (NAFLD) [7], [8]. Dietary lipids, such as cholesterol and triglycerides (TGs), have been shown to exacerbate adipose tissue infammation and non-alcoholic fatty liver disease in animal models [9], [10]. Histologically, the main feature of non-alcoholic fatty liver disease is benign steatosis, developing in 6%–55% of patients with nonalcoholic steatohepatitis (NASH) [11]. Apart from steatosis, NASH is mainly characterized by the presence of infammatory cells in the liver parenchyma cells, activation of resident macrophages (Kupfer cells [KCs]), and the fbrotic process resulting in activation of hepatic stellate cells (HSCs) [12]. Based on previous research, obesity is closely linked with nonalcoholic fatty liver disease (NAFLD), and HFD can induce obesity and steatosis [13]. While a normal liver has oxidative stress- resistant, fatty liver is vulnerable to oxidative stress. As a result of obesity resulting in fatty liver, infammation and also liver fbrosis, and steatohepatitis [14]. Our research aimed to determine the level of steatosis in Wistar rats given a standard diet, a high-fat diet, and a modifed high-fat diet and evaluate weight gain and metabolic markers in the three groups of rats.