Psychometric Properties of the Self-efficacy Scale for a Healthy Diet in Individuals with Obesity

Julio César Cortés-Ramírez, Gilda Gómez-Peresmitré, Romana Silvia Platas Acevedo, Luis Villalobos-Gallegos, Rodrigo Marín-Navarrete



Background. Self-efficacy refers to an individual’s belief in his or her capacity to execute certain behaviors and determines changes in the lifestyle of persons with chronic diseases such as obesity. There is currently no instrument with optimal psychometric properties measuring self-efficacy for a healthy diet. HAPA is a theoretical framework that can describe, explain, and predict health behavior changes and its relationship with self-efficacy, and it that is useful for the development of interventions, particularly in the area of healthy diets.

Objective. The purpose of this study was to develop an instrument to measure self-efficacy for a healthy diet in Mexican population with obesity and the evaluation of the psychometric properties of the Self-Efficacy Scale for a Healthy Diet (SSHD).

Method. The sample included 202 participants receiving care in public obesity clinics. The SSHD applied is a Likert-type scale developed from the Health Action Process Approach containing 45 items. Omega coefficient and Confirmatory Factor Analyses were estimated to evaluate the psychometric properties.

Results. The scale has good measures of goodness of fit χ2 = 66.49; p < .001; χ2 SB/gl = 41; CFIS = .955; NFI = .893; RMSEAS = .056 (95% CI [.029, .079]) and total scale reliability of ω = .896 (CI 95% [.876, .915]).

Discussion and conclusion. The SSHD is a reliable, valid instrument for measuring the three types of self-efficacies proposed in HAPA in people with obesity who require changes to adhere to a healthier diet.


Self-efficacy; behavior modification; obesity; healthy diet

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