Development and Preliminary Validation of a Multidimensional Questionnaire on Nutrition Knowledge, Food Composition Knowledge, and Dietary Habits in Medical Students

Background/Objectives: Nutrition is an important component of disease prevention and clinical care, yet nutrition training in medical education is often limited and may not adequately prepare future physicians for dietary counselling. Valid assessment tools are therefore needed to identify specific educational gaps and guide curriculum improvement. Unlike general nutrition knowledge instruments, the present questionnaire was specifically developed for medical students and integrates factual nutrition knowledge, applied food composition knowledge, and dietary habits within a multidimensional assessment framework. This study aimed to develop and preliminarily validate a multidimensional questionnaire assessing nutrition knowledge, food composition knowledge, and dietary habits in medical students. Methods: A cross-sectional psychometric validation study with a mixed-methods approach was conducted at the University of Santiago de Compostela, Spain. The instrument was developed by the research team using the revised General Nutrition Knowledge Questionnaire by Kliemann et al. as a conceptual reference and was subsequently adapted to the educational context and expected baseline knowledge of medical students. Face validity was examined through student focus groups, and content validity was established by an expert panel. The initial questionnaire included 61 analyzable items across three domains. Internal consistency was evaluated using Cronbach’s alpha, construct validity by exploratory factor analysis with Promax rotation, and sensitivity analysis was performed to refine the scale. Results: A total of 150 medical students from all six academic years participated (mean age 21.26 years). The initial instrument showed high overall internal consistency with a Cronbach’s alpha = 0.824. After excluding 15 low-performing items, the final 46-item version demonstrated improved reliability (alpha = 0.849). Domain-specific reliability was moderate for general nutrition knowledge (alpha = 0.632) and acceptable for food composition knowledge (alpha = 0.751) and dietary habits (alpha = 0.776). The revised structure produced interpretable components with potential utility for educational diagnosis. Conclusions: The refined questionnaire showed preliminary psychometric validity as a multidimensional assessment tool for medical students. Its potential value lies in providing a framework for future assessment of nutrition-related educational needs rather than in directly producing curricular or behavioral change. Independent multicenter and cross-cultural validation is required before broader use can be recommended.