Development of the plant-based nutrition knowledge scale for adults

The aim of this study was to develop a valid and reliable measurement tool to assess individuals' knowledge levels regarding plant-based nutrition. The standard scale development methodology was employed in the development of the Plant-Based Nutrition Knowledge Scale (PBNKS). The research was conducted with 304 adult participants, consisting of 43 men and 261 women. For test-retest reliability, the scale was re-administered to 60 participants two weeks after the initial application, and a positive correlation was observed between the two sets of scores (r = 0.822, p <0.001). The content validity index of the PBNKS was calculated as 0.891, and the final version of the scale consists of 22 items. Item-total correlations ranged between 0.617 and 0.814, with all items exceeding the 0.30 threshold, supporting item validity. To evaluate construct validity, Exploratory Factor Analysis (EFA) was first conducted, followed by Confirmatory Factor Analysis (CFA). EFA results revealed a four-factor structure explaining 75.70% of the total variance. These factors were identified as "Nutrient Content Knowledge," "Nutritional Awareness," "Health Perception," and "Environmental Sensitivity and Ethical Perception." CFA results indicated a good model fit ( χ²/sd = 2.32; Root Mean Square Error Of Approximation (RMSEA) = 0.028; Comperative Fit Index (CFI) = 0.964; Goodness Of Fit Index (GFI) = 0.953; Standardized Root Mean Square Residual (SRMR) = 0.062). Reliability analyses showed high internal consistency coefficients (Cronbach's Alpha = 0.948; Split-Half = 0.897–0.943; Parallel = 0.948; Strict = 0.947). Convergent validity was also supported, with Average Variance Extracted (AVE) and Composite Reliabilit (CR) values meeting the recommended thresholds. As a result, the PBNKS developed in this study was evaluated as a valid and reliable measurement instrument.