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Background Although available data suggest that some dietary flavan-3-ol sources reduce cardiometabolic risk, to our knowledge no review has systematically synthesized their specific contribution. Objective We aimed to examine, for the first time, if there is consistent evidence that higher flavan-3-ol intake, irrespective of dietary source, reduces cardiometabolic risk. Methods MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau abstracts were searched for prospective cohorts and randomized controlled trials (RCTs) published from 1946 to March 2019 on flavan-3-ol intake and cardiovascular disease (CVD) risk. Random-effects models meta-analysis was used. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach assessed the strength of evidence. Results Of 15 prospective cohorts (23 publications), 4 found highest compared with lowest habitual intakes of flavan-3-ols were associated with a 13% reduction in risk of CVD mortality and 2 found a 19% reduction in risk of chronic heart disease (CHD) incidence. Highest compared with lowest habitual intakes of monomers were associated with a reduction in risk of type 2 diabetes mellitus (T2DM) (n  = 5) and stroke (n  = 4) (10% and 18%, respectively). No association was found for hypertension. Of 156 RCTs, flavan-3-ol intervention resulted in significant improvements in acute/chronic flow-mediated dilation (FMD), systolic (SBP) and diastolic blood pressure (DBP), total cholesterol (TC), LDL and HDL cholesterol, triglycerides (TGs), hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR). All analyses, except HbA1c, were associated with moderate/high heterogeneity. When analyses were limited to good methodological quality studies, improvements in TC, HDL cholesterol, SBP, DBP, HOMA-IR, and acute/chronic FMD remained significant. In GRADE evaluations, there was moderate evidence in cohort studies that flavan-3-ol and monomer intakes were associated with reduced risk of CVD mortality, CHD, stroke, and T2DM, whereas RCTs reported improved TC, HDL cholesterol, SBP, and HOMA-IR. Conclusions Available evidence supports a beneficial effect of flavan-3-ol intake on cardiometabolic outcomes, but there was considerable heterogeneity in the meta-analysis. Future research should focus on an integrated intake/biomarker approach in cohorts and high-quality dose–response RCTs. This review was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42018035782. [ABSTRACT FROM AUTHOR]

Background: Trials have shown efficacy of rigorous diet and physical activity promotion programs to reduce diabetes incidence and improve glycemic measures in adults at increased risk for type 2 diabetes.Purpose: To evaluate diet and physical activity promotion programs for persons at increased risk for type 2 diabetes, primarily to reduce diabetes risk and decrease body weight and glycemia.Data Sources: MEDLINE, the Cochrane Central Register of Controlled Trials, CAB Abstracts, Global Health, and Ovid HealthSTAR from 1991 through 27 February 2015, with no language restriction.Study Selection: 8 researchers screened articles for single-group or comparative studies of combined diet and physical activity promotion programs with at least 2 sessions over at least 3 months in participants at increased risk for type 2 diabetes.Data Extraction: 7 researchers extracted data on study design; participant, intervention, and outcome descriptions; and results and assessed study quality.Data Synthesis: 53 studies (30 of diet and physical activity promotion programs vs. usual care, 13 of more intensive vs. less intensive programs, and 13 of single programs) evaluated 66 programs. Compared with usual care, diet and physical activity promotion programs reduced type 2 diabetes incidence (risk ratio [RR], 0.59 [95% CI, 0.52 to 0.66]) (16 studies), decreased body weight (net change, -2.2% [CI, -2.9% to -1.4%]) (24 studies) and fasting blood glucose level (net change, -0.12 mmol/L [-2.2 mg/dL] [CI, -0.20 to -0.05 mmol/L {-3.6 to -0.9 mg/dL}]) (17 studies), and improved other cardiometabolic risk factors. Evidence for clinical events was limited. More intensive programs were more effective.Limitations: Wide variation in diet and physical activity promotion programs limited identification of features most relevant to effectiveness. Evidence on clinical outcomes and in children was sparse.Conclusion: Combined diet and physical activity promotion programs are effective at decreasing diabetes incidence and improving cardiometabolic risk factors in persons at increased risk. More intensive programs are more effective.Primary Funding Source: Centers for Disease Control and Prevention Community Preventive Services Task Force. [ABSTRACT FROM AUTHOR]