FACTORS INHIBITING OPTIMAL PROTEIN UTILIZATION AMONG CHILDREN: A NARRATIVE REVIEW

Abstract

Background: Adequate protein intake is essential for child growth, yet optimal growth depends not only on protein quantity but also on the efficiency of protein utilization. Multiple biological and environmental factors may impair the conversion of dietary protein into functional body proteins, contributing to growth faltering despite sufficient protein intake. Methods: This narrative review synthesized recent evidence published between 2020 and 2026 from PubMed, Scopus, ScienceDirect, and Google Scholar. Relevant peer-reviewed studies, systematic reviews, meta-analyses, and clinical guidelines were critically reviewed to identify determinants affecting protein digestion, absorption, metabolism, and tissue protein synthesis in children. Results: Protein utilization is influenced by dietary protein quality, digestive function, intestinal absorption, environmental enteric dysfunction, gut microbiota, infection, inflammation, micronutrient status, energy adequacy, and socioeconomic and environmental conditions. These factors interact to reduce amino acid bioavailability, suppress anabolic pathways, increase protein catabolism, and impair tissue protein synthesis, thereby limiting linear growth. Conclusions: Optimizing child growth requires integrated nutrition strategies that combine high-quality protein intake with interventions supporting intestinal health, adequate energy and micronutrient intake, infection prevention, and improved environmental conditions to maximize protein utilization.