Development and Validation of Nutrition Literacy Scale for Middle School Students in Chongqing, China: A Cross-Sectional Study

Abstract Background: Nutrition literacy has a positive effect on health and its measurement has no consensus.This study was performed to develop the Chongqing Middle school student Nutrition Literacy Scale(CM-NLS)and measure its reliability and validity.Methods: Three experiments were conducted. Firstly, a theoretical framework and an initial item pool of CM-NLS were established based on the literature review. Secondly, the two-round Delphi method was used to explore the suitable acceptance indicators and items. Thirdly, item evaluation and reduction were performed using the classical test theory. In addition, the items in the final CM-NLS were tested for their validity and reliability amongst 462 middle school students.The construct validity was assessed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).The internal consistency reliability and split-half reliability were evaluated using Cronbach’s alpha coefficients.Results: The finalised CM-NLS consisting of 52 items that were based on three primary indicators (functional, interactive and critical) and six sub-indicators (obtain, understand, apply, interact, medial literacy and critical skill) was developed and validated. EFA suggested six factors explaining 69.44% of the total variance (Kaiser–Meyer–Olkin test = 0.916, Bartlett’s test χ2 = 5854.037, P < 0.001). CFA showed that the model fit the data adequately, with χ2/df = 1.911, root mean square error of approximation = 0.063, goodness-of-fit index (GFI) = 0.822 and adjusted goodness of fit index (AGFI) = 0.790. The total CM-NLS Cronbach’s alpha values of internal consistency and split-half reliability were 0.849 and 0.521, respectively, with reasonable reliability.Conclusions: CM-NLS is a valid and reliable instrument to measure nutrition literacy amongst middle school students. It provides the scientific basis for the evaluation of the nutrition literacy level of middle school students in Chongqing and the implementation of nutrition education strategies.