High Coverage, Limited Impact: Rethinking the Effectiveness of Intensive Stunting Reduction Interventions in Njombe Region, Tanzania.

Despite sustained, multisectoral investment in stunting reduction, childhood stunting prevalence in Tanzania's Njombe region has remained persistently elevated, declining only modestly from approximately 53% in 2014 to 50% by 2022. This perspective argues that the gap between intervention coverage and anthropometric impact reflects structural and conceptual limitations in current programs rather than an absence of effort or political will. Four interrelated mechanisms are examined: the conflation of stunting a lagging cumulative outcome indicator with short-term program success criteria; near exclusive reliance on anthropometric monitoring without biochemical assessment, which obscure the biological heterogeneity underlying growth faltering; the misalignment between short funding cycles and the biological time scales required for growth recovery; and fragmentation between community-based prevention and clinical nutrition services. Drawing on Njombe-specific evidence alongside global implementation literature, this paper contributes to a growing call to reframe stunting reduction as a biologically informed, adaptive process. Where the evidence base is limited, these are explicitly identified as hypotheses warranting further investigation. The recommendations advanced targeted integration of simple biochemical screening, redesigned monitoring frameworks that capture intermediate biological outcomes, and strengthened referral systems, which are practical, contextually grounded and aligned with Tanzania's existing health system architecture.