Abstract Context Obesity, particularly visceral adiposity, is associated with metabolic inflammation and increased cardiometabolic risk. Dietary interventions are essential for weight loss and improved metabolic health; however, individual responses vary widely. Circulating microRNAs are key epigenetic mediators of metabolic adaptation, although their variable expression patterns often preclude a unified biological interpretation. Objective This systematic review aims to synthesize evidence on how weight-loss diets affect the circulating microRNA profile in adults with overweight or obesity. Data Sources PubMed Central, LILACS, Scopus, Embase, Web of Science, ClinicalTrials.gov, and Google Scholar were searched without language or publication date restrictions through May 2026. Data Extraction Of 4383 records identified, 12 articles representing 9 independent randomized clinical trials met the eligibility criteria. Data on study characteristics, dietary interventions, and circulating microRNA expression profiles were extracted. Risk of bias was assessed using the Cochrane Risk of Bias 2.0 tool. Data Analysis The included studies were conducted in 6 countries and evaluated dietary interventions lasting 2–18 months. A total of 32 distinct circulating microRNAs were differentially expressed, with miR-221-3p, miR-223, miR-99b, miR-122, and miR-128 reported in more than one study. Considerable heterogeneity was observed among the dietary protocols, particularly regarding macronutrient composition. Alterations in microRNA expression were associated with weight loss, adiposity, glycemic parameters, lipid profile, inflammation, and cardiovascular risk. Bioinformatic analyses indicated enrichment of pathways related to inflammation, insulin signaling, and lipid metabolism, including the PI3K-Akt and MAPK pathways, suggesting an integrated role for these microRNAs in metabolic regulation. Conclusion Weight-loss diets modulate the circulating miRNA profile, potentially influencing glycolipid metabolism and inflammation, supporting their role as candidate biomarkers. Systematic Review Registration PROSPERO registration No. CRD42024580048.
Abstract Context Diet is a key factor shaping gut microbiota composition and function, with important implications for human health. The growing popularity of plant-based dietary patterns has increased interest in their effects on the gut microbiota. Objective This systematic review examines specific changes in gut microbiota among individuals following a plant-based diet (PBD), as well as shifts occurring after transitioning from an omnivorous diet. Data Sources PubMed and Google Scholar were searched for articles reporting original English-language human and animal studies investigating the effects of PBDs on gut microbiota composition or function. Studies published from 2015 onward were primarily considered, with most included articles published during 2020-2024. Data Extraction Four reviewers independently screened records according to eligibility criteria and extracted data on study characteristics, populations, dietary patterns, and outcomes related to gut microbiota composition and function. Data Analysis A total of 37 studies met the inclusion criteria. A PBD appeared to promote the growth of short-chain fatty acid–producing and probiotic bacteria, which help maintain intestinal integrity and support carbohydrate metabolism and may offer protection against certain diseases. A PBD was also reported to encourage the growth of beneficial taxa such as Roseburia spp., Akkermansia muciniphila, Clostridium symbiosum, and Faecalibacterium prausnitzii, which are considered indicators of a healthy microbiome. An increased Bacteroidetes/Firmicutes ratio, which was found to be a common occurrence in study participants following a PBD, correlated with a lower body mass index (BMI) and a more favorable metabolic profile, supporting healthy weight maintenance. In addition, PBDs were also associated with improvements in alpha- and beta-diversity compared with omnivorous diets. Conclusions This review indicates that PBDs appear to beneficially influence the gut microbiota and may have positive effects on human health. Nonetheless, not all studies agree on the extent or direction of microbiota changes associated with dietary patterns. Systematic Review Registration PROSPERO registration No. [CRD420251229407]; link: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251229407.
Abstract Context Plant-based meat alternatives (PBMAs) can support the transition toward healthier and more sustainable dietary patterns. However, PBMA adoption remains limited despite availability and awareness of health and environmental benefits, highlighting a gap between potential and practice. Objective This review sought to synthesize evidence on perceptions and attitudes toward PBMAs across populations and to examine how sociodemographic factors shape consumer perspectives. Data sources A comprehensive search was conducted across MEDLINE, CINAHL, Web of Science, Greenfile, and Cochrane from inception to August 2025. Data extraction This systematic review was informed by meta-ethnographic principles (4 to 6), while qualitative data were synthesized using thematic synthesis. Qualitative data from eligible studies were analyzed using a thematic synthesis assisted by ATLAS.ti software and an inductive and iterative approach for coding. Quality assessment employed the Critical Appraisal Skills Programme (CASP) checklist, and confidence in findings was evaluated using the GRADE-CERQual (Confidence in Evidence from Reviews of Qualitative Research) approach. Data analysis This review included 31 studies with a total of 2425 participants (aged 9 to > 65 years) from the Asia-Pacific (n = 14), Europe (n = 14), the United States (n = 1), and the United Kingdom (n = 4). Analysis of 914 quotations identified 6 themes (12 subthemes): with moderate GRADE-CERQual confidence, including dietary options, food ethics, dietary perceptions, food openness, food preferences, and dietary drivers; high confidence for dietary alternatives and substitutes; and low confidence for animal ethics. Younger participants (aged <18 years) linked PBMAs with identity and experimentation, while middle-aged adults showed both critical evaluation and resistance. Women demonstrated greater awareness and culinary engagement; men expressed stronger reluctance tied to masculinity. High-income countries exhibited culinary narratives linked to sociocultural values, whereas low- and middle-income countries emphasized affordability and access barriers. Conclusions Acceptance of PBMAs is shaped by intersecting sociodemographic factors that reflect broader social identities, moral values, and structural inequities. Future research should adopt intersectional and gender-informed approaches while prioritizing underrepresented low- and middle-income country contexts. PROSPERO registration CRD420251114306
Abstract Context Aging involves molecular, cellular, and functional changes that increase vulnerability to chronic disease, cognitive decline, frailty, and loss of independence. Mediterranean-style dietary patterns are generally rich in plant foods, unsaturated fats, fiber, and bioactive compounds, but their composition varies across studies and may include modified or multicomponent interventions. Objective This Systematic Review evaluated associations between Mediterranean-style dietary adherence and related interventions and markers of healthy aging, including biological aging biomarkers, cognition, frailty, physical performance, and overall health status. Data Sources PubMed, Embase, and Scopus were searched for studies published during 2013- 2025. Searches were conducted in April 2025 and updated in August 2025. The review was registered in PROSPERO (CRD420251107773). Data Extraction Randomized controlled trials (RCTs), prospective cohort studies, and cross-sectional studies in adults were eligible if they assessed Mediterranean-style dietary patterns or interventions and reported aging-related biomarkers or functional outcomes. Two reviewers independently conducted study selection and data extraction. Data Analysis Eleven studies were included: 5 RCTs, 4 prospective cohort studies, and 2 cross-sectional studies. Greater adherence was associated with better cognitive performance and slower memory decline in some studies. Favorable findings were also reported for telomere dynamics, epigenetic age, and inflammatory biomarkers. Improvements in frailty and physical performance were mainly observed in interventions combining dietary modification with physical activity. Heterogeneity in dietary definitions, adherence measures, intervention components, and outcomes precluded meta-analysis. Conclusions The evidence suggests that favorable associations exist between Mediterranean-style dietary patterns and selected markers of healthy aging but does not establish uniform or causal effects. Interpretation is limited by methodological heterogeneity, self-reported dietary exposure, and the inclusion of modified or multicomponent interventions. Long-term studies using standardized dietary definitions, harmonized outcomes, objective adherence measures, and designs capable of isolating diet-specific effects are needed. Systematic Review Registration PROSPERO registration No. [https://www.crd.york.ac.uk/PROSPERO/view/CRD420251107773].
Abstract Context Gut microbiota modulation has been proposed as an adjunct strategy for obesity management, but the additional effects of probiotics during energy restriction (ER) remain uncertain. Objective To determine whether probiotic supplementation combined with ER improves body weight and adiposity-related outcomes in adults with overweight or obesity compared with ER alone. Data Sources This systematic review and meta-analysis followed the PRISMA guidelines and was prospectively registered in PROSPERO. PubMed, Embase, Cochrane CENTRAL, and LILACS were searched through August 2025 for randomized controlled trials comparing ER plus probiotics with ER alone or ER plus placebo. Data Extraction Two reviewers independently screened the studies and extracted the data. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and certainty of evidence using GRADE. The primary outcome was body weight (BW); secondary outcomes were Body Mass Index (BMI), fat mass (FM), body fat percentage (BF%), waist circumference (WC), and fat-free mass (FFM). Data Analysis Nineteen randomized controlled trials involving 1343 participants were included, of which 16 contributed to the meta-analysis. Interventions lasted 3–20 weeks, probiotic doses ranged from 1.8 × 106 to 1.5 × 1011 colony-forming units / day, and ER ranged from fixed deficits of 300–1000 kcal/day to relative reductions of 20% to 30%. Random-effects models showed no additional effect of probiotics on BW (mean difference [MD], −0.41 kg; 95% CI, −1.21 to 0.40), BMI (−0.12 kg/m²; −0.39 to 0.15), BF% (−0.63%; −1.52 to 0.26), WC (−0.33 cm; −1.06 to 0.39), or FFM (0.03 kg; −0.18 to 0.24). A small reduction in FM favored ER plus probiotics (−0.34 kg; −0.60 to −0.08; P = .016) and remained significant after excluding high-risk-of-bias studies. Conclusion Adding probiotics to ER does not meaningfully enhance weight loss or body composition outcomes. Although FM was modestly reduced, the magnitude of the reduction was small, and its clinical relevance remains uncertain across the included randomized clinical trials overall. Systematic Review Registration PROSPERO registration No. CRD42024619326.
