A single, high-fat meal adversely affects postprandial endothelial function: a systematic review and meta-analysis.

BACKGROUND: Endothelial dysfunction is a predictive risk factor for the development of atherosclerosis and is assessed by flow-mediated dilation (FMD). Although it is known that NO-dependent endothelial dysfunction occurs after consuming a high-fat meal, the magnitude of the effect and the factors that affect the response are unquantified. OBJECTIVES: We conducted a systematic review and meta-analysis exploring the quantitative effects of a single high-fat meal on endothelial function and determined the factors that modify the FMD response. METHODS: Six databases were systematically searched for original research published up to January 2022. Eligible studies measured fasting and postprandial FMD following consumption of a high-fat meal. Meta-regression was used to analyze the effect of moderator variables. RESULTS: There were 131 studies included, of which 90 were suitable for quantitative meta-analysis. A high-fat meal challenge transiently caused endothelial dysfunction, decreasing postprandial FMD at 2 hours [-1.02 percentage points (pp); 95% CI: -1.34 to -0.70 pp; P < 0.01; I2 = 93.3%], 3 hours [-1.04 pp; 95% CI: -1.48 to -0.59 pp; P < 0.001; I2 = 84.5%], and 4 hours [-1.19 pp; 95% CI: -1.53 to -0.84 pp; P < 0.01; I2 = 94.6%]. Younger, healthy-weight participants exhibited a greater postprandial reduction in the FMD percentage change than older, heavier, at-risk groups after a high-fat meal ( P < 0.05). The percentage of fat in the meals was inversely associated with the magnitude of postprandial changes in FMD at 3 hours (P < 0.01). CONCLUSIONS: A single, high-fat meal adversely impacts endothelial function, with the magnitude of the impact on postprandial FMD moderated by the fasting FMD, participant age, BMI, and fat content of the meal. Recommendations are made to standardize the design of future postprandial FMD studies and optimize interpretation of results, as high-fat meals are commonly used in clinical studies as a challenge to assess endothelial function and therapeutics. This trial was registered at PROSPERO as CRD42020187244.

Effect of whole foods and dietary patterns on markers of subclinical inflammation in weight-stable overweight and obese adults: a systematic review.

CONTEXT: Reduction of subclinical inflammation is a potential target for chronic disease management. Adiposity is a known modifier of meta-inflammation; however, the influence of dietary factors is less clear. OBJECTIVE: This review examines evidence from human trials evaluating effects of whole foods or dietary patterns on circulating inflammatory markers in weight-stable overweight and obese adults. It is the first review to investigate effects of diet on inflammation, independent of changes in adiposity. DATA SOURCES: The Ovid MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched. DATA EXTRACTION: Data extraction was conducted using the Cochrane Collaboration Handbook for Systematic Reviews of Interventions. DATA ANALYSIS: Study quality was evaluated using the Cochrane Collaboration Risk of Bias Assessment tool. Thirty-three studies were included assessing effects of 17 foods and dietary patterns on 39 inflammatory markers. CONCLUSIONS: Overall, foods and dietary patterns were not found to have significant effects on inflammatory markers in weight-stable individuals. Inconsistencies among studies were largely due to methodological limitations. Future research should invest in longer intervention periods and standardization of inflammatory marker panels paired with novel technologies, while ensuring anthropometric measures are monitored and adequately controls are used. SYSTEMATIC REVIEW REGISTRATION: Prospero registration number CRD42017067765.