Khalafi Mousa, Rosenkranz Sara K, Ghasemi Faeghe, Kheradmand Shokoufeh, Habibi Maleki Aref, Korivi Mallikarjuna, Tsao Jung-Piao
Department of Physical Education and Sport Sciences, Faculty of Humanities, University of Kashan, Kashan, Iran.
Department of Kinesiology and Nutrition Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA.
Nutr Metab (Lond). 2025 Jan 6;22(1):1. doi: 10.1186/s12986-024-00885-x.
Intermittent fasting (IF) can be an effective dietary therapy for weight loss and improving cardiometabolic health. However, there is scant evidence regarding the role of IF on indicators of liver function, particularly in adults with metabolic disorders. Therefore, we performed a systematic review and meta-analysis to investigate the effects of IF on liver function in adults with metabolic disorders.
Three primary electronic databases including PubMed, Web of Science, and Scopus, were searched from inception to September 2024 to identify original studies that used IF interventions with or without control groups in adults with metabolic disorders. Inclusion criteria were (1) studies of human participants with metabolic diseases, (2) interventions that evaluated the effects of IF, (3) with or without a control group, and (4) measured liver fat, liver steatosis, liver fibrosis, or liver enzymes, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as primary outcomes. Standardized mean differences (SMD) and 95% confidence intervals were calculated using random effects models. Heterogeneity was assessed using the Cochran's Q statistic and I-squared statistic (I). Publication bias was assessed using the visual inspection of funnel plots and Egger's tests. The risk of bias was assessed using the PEDro scale and the NIH quality assessment tool.
A total 21 studies involving 1,226 participants with metabolic disorders were included in the meta-analysis. Overall, IF effectively decreased liver fat with a large effect size [SMD: -1.22 (95% CI: -1.63 to -0.80), p = 0.001], liver steatosis with a medium effect size [SMD: -0.73 (95% CI: -1.12 to -0.35), p = 0.001], ALT with a small effect size [SMD: -0.44 (95% CI: -0.58 to -0.30), p = 0.001], and AST with a small effect size [SMD: -0.30 (95% CI: -0.49 to -0.11), p = 0.001], but not liver fibrosis [SMD: -0.28 (95% CI: -0.59 to 0.02), p = 0.07]. Subgroup analyses showed that IF decreased liver fat and ALT significantly, independent of IF mode, participant age, health status, weight status, and intervention duration. IF significantly decreased liver fibrosis in those with obesity; and decreased AST following 5:2 diets, in middle-aged adults, adults with obesity, and regardless of health status or intervention duration.
IF seems to be an effective dietary therapy for improving liver function in adults with metabolic disorders, and many of liver function-related benefits occur regardless of IF mode, intervention duration, or participant health status.
Significant heterogeneity, small numbers of studies and inclusion of non-randomized trials or single-group pre-post trials were the main limitation of our meta-analysis. Further randomized clinical trials are needed to elucidate the effects of IF on liver function in adults with metabolic disorders.
间歇性禁食（IF）可能是一种有效的减肥和改善心脏代谢健康的饮食疗法。然而，关于IF对肝功能指标的作用，尤其是在患有代谢紊乱的成年人中的作用，证据很少。因此，我们进行了一项系统综述和荟萃分析，以研究IF对患有代谢紊乱的成年人肝功能的影响。
检索了三个主要的电子数据库，包括PubMed、Web of Science和Scopus，从数据库建立至2024年9月，以识别在患有代谢紊乱的成年人中使用IF干预且有或无对照组的原始研究。纳入标准为：（1）对患有代谢疾病的人类参与者进行的研究；（2）评估IF效果的干预措施；（3）有或无对照组；（4）测量肝脏脂肪、肝脂肪变性、肝纤维化或肝酶，包括以丙氨酸氨基转移酶（ALT）和天冬氨酸氨基转移酶（AST）作为主要结局指标。使用随机效应模型计算标准化均数差（SMD）和95%置信区间。使用Cochran's Q统计量和I²统计量（I）评估异质性。使用漏斗图的视觉检查和Egger检验评估发表偏倚。使用PEDro量表和美国国立卫生研究院质量评估工具评估偏倚风险。
荟萃分析共纳入21项研究，涉及1226名患有代谢紊乱的参与者。总体而言，IF有效降低了肝脏脂肪，效应量较大[SMD：-1.22（95%CI：-1.63至-0.80），p = 0.001]；降低了肝脂肪变性，效应量中等[SMD：-0.73（95%CI：-1.12至-0.35），p = 0.001]；降低了ALT，效应量较小[SMD：-0.44（95%CI：-0.58至-0.30），p = 0.001]；降低了AST，效应量较小[SMD：-0.30（95%CI：-0.49至-0.11），p = 0.001]，但未降低肝纤维化[SMD：-0.28（95%CI：-0.59至0.02），p = 0.07]。亚组分析表明，IF显著降低了肝脏脂肪和ALT，与IF模式、参与者年龄、健康状况、体重状况和干预持续时间无关。IF显著降低了肥胖者的肝纤维化；在5:2饮食模式下、中年成年人、肥胖成年人中，无论健康状况或干预持续时间如何均降低了AST。
IF似乎是一种改善患有代谢紊乱的成年人肝功能的有效饮食疗法，许多与肝功能相关的益处与IF模式、干预持续时间或参与者健康状况无关。
显著的异质性、研究数量少以及纳入非随机试验或单组前后试验是我们荟萃分析的主要局限性。需要进一步的随机临床试验来阐明IF对患有代谢紊乱的成年人肝功能的影响。
