Objectives: To determine the relationship between sustainable and healthy food shopping behavior comparing general motivation with the immediate intention to act.
Method: We conducted an online survey of 144 staff at the Cork Institute of Technology, Ireland, using a questionnaire based on the Theory of Planned Behavior and the Self-Determination Theory to compute the Behavioral Intention score and the Relative Autonomy Index in relation to healthy and sustainable grocery shopping.
Results: The intention to shop healthy food was higher (p < 0.001, Cohen's d = 0.56) than the intention to shop in a sustainable way. A significant intention-action gap was observed for both healthy (p < 0.001, Cohen's d = 0.97) and sustainable grocery shopping (p < 0.001, Cohen's d = 1.78). While there was a significant correlation (p < 0.001) between the longer-term motivations to act in a healthy and sustainable way, this association was not significant (p = 0.16) for the more short-term Behavioral Intention scores.
Conclusion and Implications: Health was identified as a more important driver for dietary behavior compared to sustainability. While longer-term motivation shows a stronger correlation between healthy and sustainable grocery shopping, short-term intentions do not follow this pattern as strongly. A significant intention-action gap exists for both, which is stronger for sustainability than for health.