Determinants of fruit and vegetable consumption among Saudi adults: an extended Theory of Planned Behavior approach

This study examines the determinants of fruit and vegetable consumption among Saudi adults using an extended Theory of Planned Behavior (TPB) model. The model incorporates core TPB constructs-attitudes, subjective norms, and perceived behavioral control (PBC)-along with sociodemographic, behavioral, and knowledge-related factors.

A cross sectional study was conducted on a sample of adult Saudis (n = 471). Data were analyzed using structural equation modeling, comparing a basic TPB model with an extended model that included additional predictors such as knowledge about World Health Organization (WHO) dietary recommendations, diet, family meals, and physical activity.

PBC has is a strong predictor of behavior compared to intention. For intention, attitude (unstandardized coefficients [coeff] = 0.29, standard error [se] = 0.13, p = 0.025), subjective norm (coeff = 0.37, se = 0.11, p = 0.001), and PBC (coeff = 1.29, se = 0.17, p = 0.000) are all significant predictors. The extended model explained slightly more variance in behavior (R ² = 0.45) and intention (R ² = 0.78) compared to the basic model (behavior: R ² = 0.40; intention: R ² = 0.74), highlighting the added value of these factors. PBC emerged as the strongest predictor of behavior (coeff = 0.71, se = 0.26, p = 0.006), while knowledge (coeff = 0.29, se = 0.05, p < 0.001) and family meals (coeff = 0.19, se = 0.05, p < 0.001) significantly predicted attitudes. Moderate physical activity was associated with subjective norms (coeff = 0.08, se = 0.03, p = 0.009), suggesting a synergistic relationship between physical activity and dietary behavior.

These findings underscore the importance of addressing both psychological and practical factors in interventions to promote fruit and vegetable consumption among Saudi population, with a focus on enhancing self-efficacy, leveraging family dynamics, and integrating physical activity promotion.