A cluster randomized trial protocol to evaluate the effectiveness of an integrated package of improved take-home foods complemented with social and behaviour change communication strategies to improve nutritional status in children aged 6–36 months i

Background Nutrition during early childhood is critical for growth, development, and long-term well-being, with age-appropriate complementary feeding playing a pivotal role in meeting a child’s nutritional needs. Despite concerted efforts through national programs in India, gaps persist in complementary feeding practices, contributing to the enduring burden of undernutrition. This study aims to address these gaps by developing an intervention package comprising state- and district-specific improved take-home rations (THRs) provided under the Integrated Child Development Services (ICDS) alongside socio-culturally tailored social and behaviour change communication (SBCC) strategies to improve nutrition among children aged 6–36 months. Methods The study will be conducted in one selected district from each of six Indian states—Karnataka, Madhya Pradesh, Maharashtra, Meghalaya, Odisha, and Rajasthan. The study comprises three sequential phases. In the first phase, formative research will explore current dietary practices of children aged 6–36 months, including THR uptake, as well as perceptions and challenges related to existing THR provision under ICDS and SBCC initiatives from both supply- and demand-side stakeholders. In the second phase, insights from formative research will inform co-development of an intervention package comprising optimized THR formulations and a multi-level SBCC strategy through an iterative and participatory process, which will be piloted to assess feasibility and acceptability. In the final phase, a two-arm cluster randomized controlled trial (cRCT) will evaluate the effectiveness of the intervention in improving nutritional status and complementary feeding practices compared to existing THR and SBCC strategies. cRCT will comprise: (1) a longitudinal cohort of children aged 6–18 months receiving the intervention for 18 months, with follow-up at baseline, 6, 12, 18, and 24 months to assess outcomes at individual level; and (2) repeated cross-sectional surveys of all children aged 6–36 months residing in study clusters at baseline and 6-month intervals up to 24 months to capture population-level changes. Discussion The study will demonstrate the effectiveness of improved THR products combined with socio-culturally relevant SBCC strategies in improving feeding practices and nutritional status of children aged 6–36 months, while also assessing cost-effectiveness. By prioritizing local acceptability, sustainability, and use of locally available nutrient-rich foods aligned with regional dietary preferences, the intervention aims to bridge the gap between policy intentions and community practices. Findings will inform future THR reform and complementary feeding initiatives in India. Clinical trial registration https://ctri.nic.in/Clinicaltrials/searchbyctri.php , identifier CTRI/2024/10/075472.