Psychological predictors of unhealthy eating and food security: a meta-analysis

Purpose This study aims to investigates how national food security moderates the predictive relationships proposed by the theory of planned behavior (TPB) – attitudes, subjective norms and perceived behavioral control (PBC) – in the context of unhealthy food consumption. Design/methodology/approach The authors conducted a meta-analysis of 75 studies, encompassing 427 effect sizes related to intention and behavior regarding unhealthy eating. The authors used random-effects models and meta-regressions to test the moderating role of the Global Food Security Index (GFSI), along with covariates such as sample nature, measurement strategy, behavioral framing and sample age. Findings All TPB constructs showed significant positive associations with unhealthy eating. However, GFSI significantly moderated these effects. Higher national food security levels weakened the relationships between attitudes, subjective norms, PBC and unhealthy food consumption. This suggests that in more food-secure environments, psychological predictors play a less central role in dietary decision-making. Research limitations/implications The findings advance TPB by demonstrating its conditional validity under different macrostructural conditions, reinforcing the integration of ecological and structural variables in behavioral models. Practical implications In food-secure contexts, public health interventions may benefit more from structural strategies than cognitive or motivational approaches. Conversely, in food-insecure settings, targeting attitudes and perceived control remains relevant. Social implications Tailoring health campaigns to food security contexts can increase effectiveness and support more equitable, sustainable food systems. Originality/value To the best of the authors’ knowledge, this is the first meta-analysis to integrate TPB with national food security indicators, offering novel insights into how environmental structure shapes health behavior predictors in unhealthy eating.