Poor Dietary Diversity Potentially Linked to Risk of Anemia in Adolescents

After a systematic review and meta-analysis study, investigators recently indicated a correlation between lower dietary diversity and higher odds of anemia in children and adolescents.

Micronutrient deficiencies effect an estimated 2 billion people in developing and developed countries. In addition to causing specific diseases, they exacerbate the effects of a variety of infectious and chronic diseases, impact morbidity, mortality, and life quality. For instance, folic acid deficiency is responsible for excess birth defects, and vitamin D deficiency can lead to bone fractures and osteoporosis.2

Iron deficiency anemia (IDA), manifesting in a lack of red blood cells or hemoglobin, is one of the more substantial micronutrient-deficiency concerns worldwide. IDA disparately affecting children and adolescents, especially those living in low- and middle-income countries.1

“This systematic review and meta-analysis aimed to address this gap in knowledge,” wrote Haiting Li, department of physical education, Henan University of Animal Husbandry and Economy, and colleagues. “By systematically searching and analyzing data from multiple observational studies, we aimed to provide a more robust understanding of the relationship between dietary diversity and anemia in children and adolescents.”1

Li and colleagues underwent a comprehensive search in electronic databases including PubMed, Web of Science, and Scopus, collecting studies conducted on dietary diversity. Study eligibility included a population of adolescents and children aged 0-18 years; assessment of dietary diversity as an exposure factor; higher dietary diversity compared with lower; odds of anemia, including iron deficiency anemia; and observational, cross-section and case-control, studies.1

Initial searches collected 898 studies, which was lowered to 519 after excluding duplicates and to 473 after filtering for inclusion criteria. A final total of 29 studies were included after a series of reviews to confirm eligibility. Sample size ranged from 210 to 14,669 participants.1

Investigators used 19 studies to evaluate the association between dietary diversity and odds of anemia. The data exhibited a significant correlation between inadequate dietary diversity and odds of anemia in children >5 years (odds ratio [OR] = 1.96; 95% CI 1.57-2.45; I2 = 83.6%, t2 = 0.38 P <.001). Based on an estimated baseline anemia prevalence of 40%, the absolute effect suggests around 384 additional anemia cases per 1000 children due to inadequate diet diversity.1

Of the remainder, 10 studies examined the relationship between poor dietary diversity and anemia prevalence in children and adolescents aged 6-18 years. A significant association was indicated, with a significant heterogeneity (OR = 1.73; 95% CI, 1.27-2.36; I2 = 87%, t2 = .44; P <.001). The 95% prediction interval was [.45-6.58]. With a baseline of 25% anemia prevalence, the absolute effect suggested around 183 additional cases per 1000 children due to inadequate dietary diversity.1

Li and colleagues explored small-study effects by comparing the results from the fixed-effects model with the random-effects model. For children between 0-5 years, the random-effects model showed an OR = 1.96 (95% CI, 1.57-2.45), while the fixed-effect model resulted in an OR = 1.77 (95% CI, 1.49-2.33). For children 6-18 years, the random-effects model showed an OR = 1.73 (95% CI, 1.27-2.36) and the fixed-effects model showed an OR = 1.5 (95% CI, 1.21=2.24).1

The team indicates that these data show a substantial positive correlation between inadequate dietary diversity and increased anemia odds with both groups.

“Previous studies have primarily focused on children under 5 years old, a critical period for growth and development,” wrote Li and colleagues. “This highlights the need for continued emphasis on maintaining a healthy and diverse diet throughout childhood and adolescence to ensure optimal iron intake and reduce the likelihood of anemia.”1

References

1. 1: Li H, Moosavian SP, Ghanbari N, Mirlohi SH, Rahimlou M. Association of dietary diversity and odds of anemia in children and adolescents: a systematic review and meta-analysis of observational studies. BMC Nutr. 2025;11(1):83. Published 2025 Apr 22. doi:10.1186/s40795-025-01069-3

2. 2: Tulchinsky TH. Micronutrient deficiency conditions: Global Health Issues. Public Health Reviews. 2010;32(1):243-255. doi:10.1007/bf03391600