Dietary diversity score and cardio-metabolic risk factors: an updated systematic review and meta-analysis.

Context Dietary diversity score (DDS) has been known as a useful and convenient indicator of overall diet quality. Previous studies have reported the association between DDS and health problems such as diabetes, metabolic syndrome and cardiovascular disease. Objectives This systematic review and meta-analysis aimed to assess the association between dietary diversity score (DDS) and cardio-metabolic risk factors such as obesity and overweight, lipid profile, blood pressure, metabolic syndrome (MetS) and diabetes. Data sources We systematically searched PubMed and NLM Gateway, Scopus and Institute of Scientific Information (ISI) by up to October 2019. Data extraction All observational studies which assessed the association of DDS with cardio-metabolic risk factors including anthropometric measures, blood pressure, lipid profile, glycemic indices and MetS without limitation in time of publication and language were included and critically reviewed by two independent experts. Random-effects meta-analysis was used to estimate the effect sizes. Data analysis Among 843 documents retrieved from literature search, 23 studies met the inclusion criteria for systematic review, and 18 studies were eligible for meta-analysis. Random-effects meta-analysis showed that the association of DDS with obesity, abdominal obesity, overweight, body mass index, MetS, diabetes, blood pressure, and lipid profile (TC, LDL, HDL) was not statistically significant. On the other hand, the association of DDS and TG was statistically significant (SMD: - 0.23, 95% CI - 0.45, - 0.01). Conclusions Our findings revealed that there was no significant association between DDS and cardio-metabolic risk factors. Reassessment of the overall DDS tool as a criterion of diet quality and production of new and valid DDS standard tools is highly desirable. More high-quality studies are also needed to confirm the findings of this study. Study registration This study is registered as PROSPERO CRD42020157127. Level of evidence Level I, systematic reviews and meta-analyses.