Association of dietary diversity and odds of anemia in children and adolescents: a systematic review and meta-analysis of observational studies.

BACKGROUND

Anemia, characterized by a deficiency in red blood cells or hemoglobin, remains a significant public health concern worldwide, particularly among children and adolescents. Inadequate dietary intake, including micronutrient deficiencies, has been associated with anemia. Dietary diversity, characterized by the consumption of a variety of food groups, may contribute to adequate iron intake and a reduced likelihood of anemia. This systematic review and meta-analysis examined the association between dietary diversity and odds of anemia among children and adolescents.

METHODS

A comprehensive search of electronic databases (PubMed, Web of Science, Scopus) was conducted for observational studies (cross-sectional or case-control) published before April 2024 that assessed the association between dietary diversity and anemia among children and adolescents. The odds of Bias in Non-Randomized Studies of Exposures (ROBINS-E) tool was used to assess the quality of included studies, ensuring a standardized and rigorous evaluation process. Subgroup analyses explored potential variations in this association based on age group, geographic location, and type of anemia.

RESULTS

Nineteen studies (18 cross-sectional and 1 case-control) examined the association between dietary diversity and anemia in children under 5 years old. Pooled analysis revealed a significant association between lower dietary diversity and higher odds of anemia among children aged 0 to 5 years (OR = 1.96; 95% CI: 1.57, 2.45; I = 83.6%, τ2 = 0.38 P < 0.001). Ten studies examined the relationship in children and adolescents aged 6-18 years, showing a similar pattern (OR = 1.73; 95% CI: 1.27, 2.36; I = 87%, τ2 = 0.44; P < 0.001). Subgroup analyses suggested that the association varied across specific geographic regions.

CONCLUSIONS

This meta-analysis indicates a significant association between lower dietary diversity and higher odds of anemia in children and adolescents. These findings underscore the importance of dietary diversity as a potential factor related to anemia prevalence. Future research should focus on standardizing dietary diversity assessment methods and incorporating detailed dietary quality measurements.