Four Dietary Items of the School Physical Activity and Nutrition (SPAN) Questionnaire Form a Robust Latent Variable Measuring Healthy Eating Patterns

Abstract Objective Evaluate the factor structure and stability of 4 dietary items (fruit, fruit juice, vegetables, and milk) from the School Physical Activity and Nutrition questionnaire–elementary school version. Methods Secondary analysis of intervention data from third graders measured at pre-intervention, post-intervention (10 weeks), and 3-month follow-up. The researchers conducted structural equation modeling invariance analysis to test the stability of the factor structure of the 4 items. Results Data from 1,147 students. Fit indices revealed good fit for a single factor remaining stable across time (χ 2 /degrees of freedom [DF] = 59.75/59, P = .45), gender (χ 2 /DF = 149.72/128, P = .09), and study groups (χ 2 /DF = 143.04/128, P = .17). Conclusions and Implications A healthy food factor consisting of the 4 items can be used in future data analysis. This offers several advantages in analysis, including the use of latent change scores that are more powerful, more informative, and more easily interpreted than traditional approaches.