Association Between Dietary Diversity Score and Obesity Indices Among Adults: A Systematic Review and Meta-Analysis

Abstract

The relationship between Dietary Diversity Score (DDS) and obesity remains unclear, with previous studies reporting conflicting results across populations and dietary contexts. This systematic review and meta-analysis aimed to examine the association between DDS and obesity indices, including Body Mass Index (BMI), Waist Circumference (WC), and abdominal obesity, among adults. A comprehensive search was conducted in PubMed, Scopus, Web of Science, and Embase up to December 2025, with no time restrictions. Observational studies assessing the association between DDS and anthropometric indices in adults were included. Data were pooled using a random-effects model, and heterogeneity was assessed using the I² statistic. Subgroup analyses were performed according to sex, country, sample size, and DDS assessment method. There were 27 studies in all, including 11,308 adults from 16 different nations. To calculate DDS, the majority of studies either used a Food Frequency Questionnaire (FFQ) or 24-hour dietary recalls. While there was a little positive correlation between DDS and overweight, the pooled effect size showed no meaningful correlation between DDS and obesity. Abdominal obesity and DDS were not shown to be significantly correlated. Studies showed a high degree of heterogeneity, which can be partially attributed to variations in sex, geography, and DDS assessment instruments. The findings suggest that dietary diversity alone may not protect against obesity and could be associated with increased energy intake in some populations. Variations in dietary patterns, food quality, and DDS assessment methods may explain the inconsistent associations observed across studies. Higher DDS was not significantly associated with obesity or abdominal obesity, but showed a small positive association with overweight. These findings suggest that while dietary diversity reflects nutritional adequacy, it may also contribute to higher energy intake and body weight in some contexts. Public health recommendations should therefore emphasize the quality rather than the quantity of dietary diversity, promoting nutrient-dense rather than energy-dense foods. Further longitudinal studies with standardized DDS assessment are needed to clarify these associations.