Effectiveness of Nutritional Support on Anthropometric Outcomes in Malnourished Children Under 5 Years

Background Malnutrition remains a major public health issue among children under 5 years in resource-limited settings, impairing growth, cognitive development, and long-term health outcomes. In Iran, the participatory-supportive child nutrition improvement program has been scaled nationally since 2005. This study evaluated the effectiveness of this program in improving key nutritional indicators among malnourished children. Methods We conducted a community-based quasi-experimental trial with individual randomization and frequency-matched controls in urban city area of Mashhad, Iran. Malnourished children aged 6–60 months (n = 264) were enrolled from September 2024, with 264 completing 9-month follow-up (intervention = 131, control = 98). The intervention provided monthly food credits (6–11 million rials), customized baskets meeting caloric and macronutrient needs across four age strata, nutritional counseling, and bimonthly growth monitoring. Controls received routine care. Outcomes included changes in weight-for-age (WAZ), height-for-age (HAZ), and weight-for-height (WHZ) z-scores. Results At baseline, controls were older and had significantly higher weight, height, and z-scores (all P < 0.001) and economic decile (p < 0.05) compared to the intervention group due to matching constraints. Over 9 months, the intervention group exhibited significant within-group gains in height (P < 0.001), HAZ (P = 0.02), and WHZ (P < 0.001). Improvements in stunting (42.1% vs. 31.1%) and wasting (26.5% versus 22.1%) were higher, and worsening of underweight was lower (11.3% versus 18.5%) in the intervention compared to the control group. However, the differences between groups were not statistically significant after adjusting for confounders. Conclusion This intervention program accelerated linear growth and acute nutritional improvement trajectories in an urban group with high financial burden.