We aimed to fully review the association of empirical dietary patterns with the risk of noncommunicable chronic diseases and to rate the quality of the evidence. Published meta-analyses of observational studies investigating the association of empirically-derived dietary patterns with the risk of chronic diseases were identified by searching PubMed and Scopus till September, 2019. Two independent reviewers extracted the information and rated the quality of the evidence by NutriGrade score. For each meta-analysis, cross-sectional and case-control studies were excluded and then, summary relative risk (SRR) was recalculated by using a random-effects model. Sixteen meta-analyses of prospective cohort studies, reporting 18 SRRs for healthy dietary patterns and 16 SRRs for unhealthy patterns obtained from 116 primary prospective cohort studies with 4.8 million participants, were included. There was moderate quality of evidence for the inverse association of healthy dietary patterns with the risk of type 2 diabetes, fracture, and colorectal and breast cancers. There was also low quality evidence for the inverse relation between healthy dietary patterns and the risk of all-cause and cardiovascular mortality, depression, and coronary heart and respiratory diseases. There was moderate quality of evidence for a positive association between unhealthy dietary patterns and the risk of type 2 diabetes, fracture, and metabolic syndrome. Adopting a healthy dietary pattern may reduce the risk of type 2 diabetes, coronary heart disease, and premature death. More research is needed for outcomes for which the quality of the evidence was rated low, such as respiratory disease, mental illness, and site-specific cancers.

A previous meta-analysis provided convincing evidence for an inverse association between adherence to a Mediterranean diet (MedDiet) and the risk of all-cause mortality. Since then, 19 prospective studies have been published. We updated the evidence from these prospective studies and conducted a dose-response meta-analysis to test the linear and potential nonlinear dose-response associations between adherence to a MedDiet and the risk of all-cause mortality. The PubMed, Scopus, ISI Web of Knowledge, and Embase bibliographic databases were systematically searched up to August 24, 2018. Summary HRs were estimated with the use of a random-effects meta-analysis to assess the association between a 2-point increment in MedDiet adherence and the risk of all-cause mortality. Sensitivity and subgroup analyses were performed and potential publication bias was tested. Twenty-nine prospective studies with 1,676,901 participants and 221,603 cases of all-cause mortality were included in the final analysis. The pooled HR of all-cause mortality was 0.90 (95% CI: 0.89, 0.91; I2 = 81.1%) for a 2-point increment in adherence to a MedDiet. Subgroup analyses showed that a significant inverse association was stronger in participants who lived in the Mediterranean region compared with non-Mediterranean areas (HRs: 0.82 compared with 0.92, respectively), and in studies that used the Panagiotakos MedDiet score. A nonlinear dose-response meta-analysis indicated that the risk of all-cause mortality linearly decreased with the increase in adherence to a MedDiet. The robustness of findings was confirmed in the sensitivity analyses. In conclusion, low-quality evidence from prospective cohort studies suggests an inverse association between adherence to a MedDiet and the risk of all-cause mortality, especially in Mediterranean regions. An inverse linear dose-response relation was also observed between adherence to a MedDiet and the risk of all-cause mortality.

Objective: To systematically assess the association of circulating inflammation markers with the future risk of hypertension. Methods: We did a systematic literature search of PubMed and Scopus, from database inception to July 10, 2018. Prospective and retrospective cohort studies evaluating the association of circulating C reactive protein (CRP), high-sensitive CRP (hs-CRP), interleukin 6 (IL-6) and IL-1β to the risk of developing hypertension in the general population were included. The relative risks (RRs) for the top versus bottom tertiles of circulating biomarkers were calculated using a fixed-effects/random-effects model. A potential non-linear dose-response association was tested. Results: Fourteen prospective cohort studies, two retrospective cohort studies and five nested case-control studies involving 142 640 participants and 20 676 cases were identified. The RR for the third versus first tertiles of circulating CRP was 1.23 (95% CI 1.11 to 1.35; I²=59%, n=12). The association remained unchanged after adjustment for body mass index. The RRs for other biomarkers were as follows: hs-CRP (RR 1.20, 95% CI 1.02 to 1.37; I²=74%, n=7), IL-6 (RR 1.51, 95% CI 1.30 to 1.71; I²=0%, n=5), and IL-1β (RR 1.22, 95% CI 0.92 to 1.51; I²=0%, n=3). A non-linear dose-response meta-analysis demonstrated that the risk of hypertension increased linearly with increasing circulating inflammation markers, even within the low-risk and intermediate-risk categories. Conclusions: Higher levels of circulating CRP, hs-CRP and IL-6, but not IL-1β, were associated with the risk of developing hypertension. The association persisted in subgroups of studies defined by major sources of heterogeneity.

Background: Although previous investigations have proposed an association between Dietary Approaches to Stop Hypertension (DASH)-style diet and lower mortality from chronic diseases, the exposure-response relationship is not clear. The present systematic review andmeta-analysis aimed to explore the linear and non-linear dose-responseassociation between adherence to the DASH diet andall-cause and cause-specific mortality.Methods: Database search was performed in PubMed, Scopus, and EMBASE for prospective cohort studies investigating the association between adherence to the Dietary Approaches to Stop Hypertension (DASH) diet and risk of mortality. Summary hazard ratios (HRs) and 95% confidence intervals (CI) were estimated with the use of a random-effects model for the linear and nonlinear relationships. The two-stage hierarchical regression model was applied to test the potential non-linear dose-response associations.Results: The inclusion criteria were met by 17 studies (13 publications). The scores reported for adherence to the DASH diet in different studies were converted to a conventional scoring method in which the adherence score might range between 8 to 40. The linear analysis revealed that summary HRs were 0.95 (95% CI: 0.94–0.96, I² = 91.6%,n = 14) for all-cause, 0.96 (95% CI: 0.95–0.98, I² = 82.4%,n = 12) for CVD, 0.97 (95% CI: 0.96–0.98, I² = 0.00%,n = 2) for stroke, and 0.97 (95% CI: 0.95–0.98, I² = 63.7%,n = 12) for cancer mortality per each 5-point increment of adherence to the DASH diet. There was also evidence of non-linear associations between the DASH diet and all-cause and cause-specific mortality as the associations became even more evident when the adherence scores were more than 20 points (P < 0.005).Conclusion: Even the modest adherence to the DASH diet is associated with a lower risk of all-cause and cause-specific mortality. The higher adherence to the diet also strengthens the risk-reducing association.Registration: This review was registered in the international prospective register of systematic reviews (PROSPERO) database (registration ID: CRD42018086500).

Importance: Current guidance on the duration of aerobic exercise recommended in existing guidelines comes primarily from individual trials. Meta-analyses are lacking to examine the dose-response association of aerobic exercise with adiposity measures.Objective: To clarify the dose-response association of aerobic exercise with adiposity measures.Data Sources: PubMed, Scopus, the Cochrane Central Register of Controlled Trials, and gray literature sources (ProQuest and ClinicalTrials.gov) from inception to April 30, 2024.Study Selection: Randomized clinical trials with intervention durations of at least 8 weeks evaluating the effects of supervised aerobic training on adults with overweight or obesity.Data Extraction and Synthesis: The PRISMA guidelines were followed to report the results of the meta-analysis. Data extraction was conducted by 2 teams of 2 reviewers each, working independently and in duplicate. Random-effects meta-analyses were performed to estimate mean differences and 95% CIs for each 30-minute per week aerobic exercise and to clarify the shape of the curvilinear associations.Main Outcomes and Measures: Measures of body weight, waist circumference, body fat, adverse events, medication use reduction, and health-related quality of life score. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool, with a range from very low to high certainty.Results: In total, 116 randomized clinical trials involving 6880 participants (4199 [61%] female; mean [SD] age, 46 [13] years) with overweight or obesity were included. Each 30 minutes per week of aerobic exercise was associated with reduced body weight by 0.52 kg (95% CI, −0.61 to −0.44 kg; n = 109 trials, GRADE = moderate), waist circumference by 0.56 cm (95% CI, −0.67 to −0.45 cm; n = 62 trials, GRADE = high), body fat percentage by 0.37% (95% CI, −0.43% to −0.31%; n = 65 trials, GRADE = moderate), as well as the areas of visceral (mean difference, −1.60 cm² [95% CI, −2.12 to −1.07 cm²]; n = 26 trials, GRADE = high) and subcutaneous (mean difference, −1.37 cm² [95% CI, −1.82 to −0.92 cm²]; n = 27 trials, GRADE = moderate) adipose tissues. Aerobic exercise was associated with modestly increased physical (standardized mean difference, 1.69 SD [95% CI, 1.18-2.20 SD]) and mental (standardized mean difference, 0.74 SD [95% CI, 0.29-1.19 SD]) aspects of quality of life (1 trial with 80 participants, GRADE = low). It was associated with modestly increased mild to moderate adverse events, which were mostly musculoskeletal symptoms (risk difference, 2 more events per 100 participants [95% CI, 1 to 2 more]; GRADE = low). Dose-response meta-analyses indicated that body weight, waist circumference, and body fat measures decreased linearly or monotonically in association with increasing duration of aerobic exercise to 300 minutes per week, with aerobic exercise lasting 150 minutes per week at moderate to vigorous intensities resulting in clinically important reductions in waist circumference and body fat.Conclusions and Relevance: In this meta-analysis of randomized clinical trials, engaging in 30 minutes of aerobic exercise per week was associated with modest reductions in body weight, waist circumference, and body fat measures among adults with overweight or obesity. However, aerobic training exceeding 150 minutes per week at moderate intensity or greater may be needed to achieve clinically important reductions.