The correlation between nutrition index scores and nutrition status of preschool children in a district of Shanghai

< 0.05). The intervention stabilized BMI in normal-weight children and improved nutritional outcomes in underweight and overweight subgroups. These findings suggest the potential effectiveness of family-centered dietary management and structured physical activity in enhancing children's nutritional quality, particularly for those with elevated BMIZ. Tailored interventions based on individual BMIZ classifications are recommended to optimize health outcomes. This study provides evidence-based insights for designing targeted strategies to address childhood malnutrition and obesity.