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

BACKGROUND: Time-restricted eating (TRE) may facilitate weight loss, but its impact on inflammation remains unclear. Chronic inflammation can detrimentally increase risk of obesity-associated comorbidities. OBJECTIVES: The aim of this systematic review was to synthesize and determine the effects of TRE on cytokine and adipokines (C-reactive protein [CRP], TNF alpha [TNF-α], interleukin-6 [IL-6], leptin, and adiponectin) in adults. METHODS: 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 23 June, 2023. Risk of bias was assessed using risk of Bias 2 tool 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. RESULTS: A total of 25 studies (13 RCTs, 12 non-RCTs) involving 936 participants were included. The pooled SMD for the effect of TRE compared with the control group on cytokines and adipokines was -0.11 (95% CI: -0.33, 0.12; I2 = 19.7%; n = 10 comparisons) for CRP; -0.25 (95% CI: -0.47, -0.03; I2 = 0%; n = 11 comparisons) for TNF-α; -0.09 (95% CI: -0.39, 0.21; I2 = 16.4%; n = 8 comparisons) for IL-6; -0.81 (95% CI: -1.37, -0.24; I2 = 65.3%; n = 5 comparisons) for leptin; and 0.07 (95% CI: -0.40, 0.54; I2 = 56.9%; n = 6 comparisons) for adiponectin. CONCLUSIONS: Time-restricted eating may be an effective approach to reduce TNF-α and leptin levels in the general adult population. This review was registered at PROSPERO as CRD42022358162.

Putting ATM to BED: How Adipose Tissue Macrophages Are Affected by Bariatric Surgery, Exercise, and Dietary Fatty Acids.

With increasing adiposity in obesity, adipose tissue macrophages contribute to adipose tissue malfunction and increased circulating proinflammatory cytokines. The chronic low-grade inflammation that occurs in obesity ultimately gives rise to a state of metainflammation that increases the risk of metabolic disease. To date, only lifestyle and surgical interventions have been shown to be somewhat effective at reversing the negative consequences of obesity and restoring adipose tissue homeostasis. Exercise, dietary interventions, and bariatric surgery result in immunomodulation, and for some individuals their effects are significant with or without weight loss. Robust evidence suggests that these interventions reduce chronic inflammation, in part, by affecting macrophage infiltration and promoting a phenotypic switch from the M1- to M2-like macrophages. The purpose of this review is to discuss the impact of dietary fatty acids, exercise, and bariatric surgery on cellular characteristics affecting adipose tissue macrophage presence and phenotypes in obesity.