Development and validation of NutriSmart: A mobile application for nutrition education in South Indian preschool children

<h2>Abstract</h2><h3>Problem considered</h3> Early childhood nutrition education tools lack cultural relevance for South Indian populations, with no existing applications specifically designed for preschool children aged 3-6 years. Poor dietary patterns established during this critical period persist into adulthood, contributing to long-term health complications. <h3>Methods</h3> A user-centered design approach was employed involving stakeholder consultation (n = 15 across focus groups and individual interviews), development of a 1023-item South Indian food database using ICMR-IFCT 2017, and psychometric validation with 35 parents of preschool children over one month in Thiruvananthapuram district, Kerala. Content validity (expert review), face validity, internal consistency reliability (Cronbach's α), and test-retest reliability were assessed across four domains: usability, content quality, perceived effectiveness, and trust. <h3>Results</h3> Content validity was confirmed by expert panel (I-CVI: 0.80-1.00, S-CVI/Ave: 0.92). NutriSmart demonstrated high internal consistency (α = 0.82-0.89) and excellent test-retest reliability (ICC = 0.85-0.91) across all domains. The application achieved a user-centered design score of 9/11, comparable to established paediatric nutrition applications. User feedback during testing led to iterative improvements including enhanced food selection interface and expanded allergen profiles (8 to 14 items). <h3>Conclusion</h3> NutriSmart is a psychometrically validated, culturally relevant digital nutrition education tool for South Indian preschool children, demonstrating strong preliminary validity, reliability, and user acceptance for promoting healthy eating behaviors in early childhood.