AIM:To evaluate the effects of low calorie diet (LCD) onnonalcoholic steatohepatitis (NASH) in rats with obesity andhyperlipidemia.METHODS:29 Sprague-Dawley (SD) rats were randomlydivided into three groups.The animals in control (n=9) andNASH group (n=10) were fed on standard rat diet and highfat diet respectively for 12 weeks,ten rats in LCD group werefed on high fat diet for 10 weeks and then low calorie diet for2 weeks.At the end of the experiment,body weight,abdominaladipose content,liver function,and hepatopathologicalchanges were examined to evaluate the effect of differentfeeding protocols on the experimental animals.RESULTS:There was no death of animal in the experimentalperiod.All rats in the NASH group developed steatohepatitisaccording to liver histological findings.Compared with thecontrol group,body weight (423.5±65.2 vs 351.1±43.0 g,P<0.05),abdominal adipose content (14.25±1.86 vs9.54±1.43,P<0.05),liver index (3.784±0.533 vs2.957±0.301%,P<0.01),total serum cholesterol (1.60±0.41 vs 1.27±0.17 mmol/L,P<0.05)and free fatty acids (728.2±178.5 vs 429.2±96.7 mmol/L,P<0.01),serum alanine aminotransferase (1 257.51±671.34vs671.34±118.57 nkat/L,P<0.05) and aspartic aminotransferse(2 760.51±998.66 vs 1 648.29±414.16 nkat/L,P<0.01) weresignificantly increased in the NASH group.Whereas,when ratswere fed on LCD protocol,their body weight (329.5±38.4 g,P<0.01),abdominal adipose content (310.21±1.52 g,P<0.05),liver index (3.199±0.552 %,P<0.05),and serum alanineaminotransferase (683.03±245.49 nkat/L,P<0.05) weresignificantly decreased,and the degree of hepatic steatosis(P<0.05) was markedly improved compared with those inthe NASH group.However,no significant difference wasfound in serum lipid variables and hepatic inflammatorychanges between the two groups.CONCLUSION:LCD might play a role in the preventionand treatment of obesity and hepatic steatosis in SD rats,but it exerts no significant effects on both serum lipiddisorders and hepatic inflammatory changes. AIM: To evaluate the effects of low calorie diet (LCD) onnonalcoholic steatohepatitis (NASH) in rats with obesity and hyperlipidemia. METHODS: 29 Sprague-Dawley (SD) group (n = 10) were fed on standard diet and high diet for 12 weeks, ten rats in LCD group werefed on high fat diet for 10 weeks and then low calorie diet for 2 weeks. At the end of the experiment, body weight , abdominaladipose content, liver function, and hepatopathological changes were examined to evaluate the effect of differentfeeding protocols on the experimental animals.RESULTS: There was no death of animal in the experimental period. All rats in the NASH group developed steatohepatitisaccording to liver histological findings. Compared with thecontrol group, body weight (423.5 ± 65.2 vs 351.1 ± 43.0 g, P <0.05), abdominal adipose content (14.25 ± 1.86 vs9.54 ± 1.43, P <0.05) , P <0.01), total serum cholester (1.60 ± 0.41 vs 1.27 ± 0.17 mmol / L, P <0.05) and serum levels of aminotransferase (1 257.51 ± 671.34 vs 67.1.34 ± 0.72 mmol / L, 728.2 ± 178.5 vs 429.2 ± 96.7 mmol / L, P < 118.57 nkat / L, P <0.05) and aspartic aminotransferse (2 760.51 ± 998.66 vs 1 648.29 ± 414.16 nkat / L, P <0.01) weresignificantly increased in the NASH group. Thereas, when ratswere fed on LCD protocol, their body weight ( 329.5 ± 38.4 g, P <0.01). The levels of abdominal adipose content (310.21 ± 1.52 g, P <0.05), liver index (3.199 ± 0.552%, P0.05) and serum alanine aminotransferase (683.03 ± 245.49 nkat / L, 0.05) weresignificantly decreased, and the degree of hepatic steatosis (P <0.05) was markedly improved compared with those inthe NASH group. However, no significant difference was found in serum lipid variables and hepatic inflammatory changes between the two groups. CONCLUSION: LCD might play a role in the prevention and treatment of obesity and hepatic steatosis in SD rats, but it exerts no significant effects on both serum lipid disorders and hepatic inflammator y changes.