The effects of time-restricted eating vs habitual diet on inflammatory cytokines and adipokines in the general adult population: A systematic review with meta-analysis.

Time restricted eating (TRE) facilitates weight loss, but its impact on inflammation remains unclear. Chronic inflammation can detrimentally increase the risk of obesity-associated comorbidities. The aim of this systematic review was to synthesize and determine the effects of TRE on cytokine and adipokines (C-reactive protein [CRP], Tumor necrosis factor alpha [TNF-α], Interleukin-6 [IL-6], leptin, and adiponectin) in adults. PubMed, Scopus, Cochrane CENTRAL, and Web of Science were systematically searched for randomized controlled trials (RCTs) and non-RCTs to determine the effects of TRE on cytokines and adipokines in adults up to June 23rd 2023. The risk of bias was assessed using RoB2 for RCTs and the ROBINS-I for non-RCTs. The standardized mean differences (SMDs) and their 95% confidence intervals (CIs) were estimated with the DerSimonian–Laird method through random-effect models. The PRISMA recommendations were followed. A total of 25 studies (13 RCTs, 12 non-RCTs) involving 936 participants were included. The pooled SMD for the effect of TRE vs. the control group on cytokines and adipokines was -0.11 (95% CI: -0.33 to 0.12; I2=19.7%; n=10 comparisons) for CRP, -0.25 (95% CI: -0.47 to -0.03; I2=0%; n=11 comparisons) for TNF-α, -0.09 (95% CI: -0.39 to 0.21; I2=16.4%; n=8 comparisons) for IL-6, -0.81 (95% CI: -1.37 to -0.24; I2=65.3%; n=5 comparisons) for leptin and 0.07 (95% CI: -0.40 to 0.54; I2=56.9%; n=6 comparisons) for adiponectin. TRE may be an effective approach to reduce TNF-α and leptin levels in the general adult population.