This study examines the impact of a community-based nutrition intervention on childhood malnutrition in Tanzanian villages over a twelve-month period. A mixed-methods approach was employed, combining quantitative data collection through standardised assessments of nutritional status and qualitative insights gathered via focus group discussions and interviews with community members. Children in villages implementing the nutrition intervention showed a statistically significant improvement in dietary diversity (p < .05; CI: [12%, 34%]) compared to control areas, while caregivers reported increased awareness of balanced feeding practices. The findings suggest that community-based interventions can lead to measurable improvements in nutritional status and bio-social practices. However, sustained effort is needed to ensure long-term health benefits. Future research should focus on scaling up successful models and investigating the sustainability of these changes over more extended periods. Community-Based Nutrition Intervention, Childhood Malnutrition, Bio-Social Change, Tanzanian Villages Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.