Effects Of Ketogenic Diets On Obese Adults With Non-Alcoholic Fatty Liver Disease:A Meta-Analysis

Objective In order to evaluate the efficacy of ketogenic diets(KD)on obese adults with non-alcoholic fatty liver disease(NAFLD)by evidence-based methods,and to provide new direction of intervention for non-drug treatments of NAFLD.Methods By searching electronic data include Pub Med,Cochrane Library,Web of Science,Embase,CNKI,Wan fang,VIP and CBM,we collected intervention researches about KD on NAFLD which were published domestically and abroad before December 2021.Cochrane ROB and MINORS scales would be used to evaluate the methodological quality of the randomized controlled study(RCT)and the non-randomized study(NRS)respectively.Outcomes such as Weight,body mass index(BMI),total cholesterol(TC),triglycerides(TG),low density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C),alanine aminotransferase(ALT),aspartate aminotransferase(AST),γ-glutamyl aminotransferase(γ-GT),Waist,homeostasis assessment model for insulin resistance(HOMA-IR),and the liver steatosis grades would be showed through Review Manager 5.3,Stata 14.0 and Excel software.Results A total of 11 studies were included in this meta-analysis,including 3 RCTs and 8NRS studies;462 cases in the intervention group and 429 cases in the control group.The results of this meta-analysis showed that the outcomes such as Weight,BMI,TC,TG,LDL-C,γ-GT,Waist and HOMA-IR improved and the differences were statistically significant after the dietary intervention(SMD=-0.60,95%CI:-0.86～-0.35,P<0.00001;SMD=-2.98,95%CI:-3.50～-2.45,P<0.00001;SMD=-0.86,95%CI:-1.29～-0.44,P<0.0001;SMD=-0.66,95%CI:-0.80～-0.52,P<0.00001;SMD=-0.54,95%CI:-0.84～-0.23,P=0.0006;SMD=-0.48,95%CI:-0.63～-0.32,P<0.00001;MD=-6.45,95%CI:-7.96～-4.94,P<0.00001;SMD=-0.73,95%CI:-1.07～-0.39,P<0.0001).Although outcomes of HDL-C,ALT and AST improved after the dietary intervention,the differences were not statistically significant(SMD=0.22,95%CI:-0.26～0.70,P=0.38;SMD=-0.33,95%CI:-0.67～0.00,P=0.05;SMD=-0.20,95%CI:-0.50～0.10,P=0.20).The change of hepatic steatosis showed an obviously downward trend after the dietary intervention.The number of grades 0 and 1 increased significantly compared with pre-intervention,and the number of grades 2 and 3 decreased significantly.Conclusion The intervention efficacy of KD on NAFLD is worthy of recognition.It can improve visceral obesity,blood lipids,liver enzymes,insulin resistance and liver histology in obese patients with NAFLD,so as to improve or even reverse hepatic steatosis.In addition,in the study,we found that there is a correlation between the intervention effect and the intervention time,but the specific connection still needs to be further explored.