Nutrition, Growth Biomarkers, And Social Inequities In Childhood Stunting: A Systematic Review And Meta-Analysis Of 175 Studies (2003–2025)

Abstract

Stunting remains one of the most persistent global challenges affecting children under five, driven by complex interactions involving nutritional inadequacy, suppressed endocrine function, environmental enteric dysfunction, recurrent infections, and entrenched socioeconomic disparities. Although numerous studies have examined individual determinants, no prior comprehensive meta-analysis has synthesized evidence across nutritional, biological, and social domains simultaneously. This systematic review and meta-analysis aimed to integrate findings from diverse contexts to clarify the magnitude and pathways through which nutrition, growth biomarkers, inflammatory processes, and structural determinants influence stunting. Following PRISMA-2020 guidelines, a systematic search was conducted across six major databases. A total of 3,150 records were identified, and 2,975 were screened after deduplication. Of the 420 full-text articles assessed, 175 met eligibility criteria and were included in the qualitative synthesis, while 120 provided sufficient data for quantitative meta-analysis. Eligible studies included observational designs, randomized trials, quasi-experiments, and biomarker analyses conducted among children aged 0–59 months. Data extraction encompassed anthropometric outcomes; nutritional exposures; endocrine markers such as IGF-1, IGFBP-3, and alkaline phosphatase; inflammatory and EED biomarkers; and social or environmental determinants. Across the included evidence, consistent patterns emerged. Higher dietary quality particularly animal-source foods and micronutrient-dense complementary feeding was positively associated with linear growth. Biomarker studies demonstrated that children with stunting consistently exhibited lower IGF-1 and related anabolic markers, supporting a central role of GH–IGF-1 axis suppression in chronic growth impairment. Elevated inflammatory and EED markers were also associated with reduced height-for-age, indicating the importance of subclinical gut dysfunction and infection-related growth inhibition. Social determinants, including low maternal education, household food insecurity, inadequate WASH conditions, and environmental contaminant exposure, independently contributed to stunting across multiple settings. Meta-regression indicated that socioeconomic context, infection burden, and assay variability moderated effect sizes. In conclusion, stunting reflects a multisystem condition shaped by intertwined nutritional, hormonal, inflammatory, and structural factors. These findings underscore the importance of integrating endocrine biomarkers—particularly IGF-1—into growth monitoring, while emphasizing the need for coordinated multisectoral interventions to accelerate reductions in global stunting.