Dietary diversity score and obesity: a systematic review and meta-analysis of observational studies

BACKGROUND/OBJECTIVES: Studies examining the association between dietary diversity score (DDS) and obesity have led to inconsistent findings. Therefore, the purpose of this review is to summarize and elucidate the source of heterogeneous results reported in different studies. METHODS: PubMed, ISI Web of Science, Scopus and Google Scholar were searched through December 2013 to identify all relevant articles. Sixteen publications met the inclusion criteria for the systematic review and 10 articles were entered into the meta-analysis. Eight studies had data on the odds ratio (OR) for overweight/obesity and eight compared the mean body mass index (BMI) among subjects with highest versus the lowest DDS. RESULTS: A meta-analysis on eligible studies failed to show a significant association on either overweight/obesity OR (OR: 0.72; 95% confidence interval (CI): 0.45-1.16; P = 0.174) or mean differences (MD) in BMI (MD: 0.22; 95% CI: - 0.70-1.14; P = 0.643) comparing the highest and lowest diverse diets. Between-study heterogeneity was high, and subgroup analysis failed to identify the source of heterogeneity. CONCLUSIONS: Our systematic review and meta-analysis showed that there was no significant association between DDS and BMI status, which may be due to use of different methods for assessing dietary intake and determination of DDS. Thus, well-designed prospective studies with similar approaches to assess DDS are highly recommended.