Chavis Ketkaew, Yollada Komsing
As eco-labeled food products proliferate in retail environments, understanding the drivers of sustainable purchase decisions has become increasingly urgent. This study examines how health benefit claims, ethical practice claims, and environmental impact claims influence perceptions of eco-label information quality (ELQ), and how ELQ subsequently shapes sustainable purchase intention (SPI) through the Theory of Planned Behavior (TPB) mechanisms—attitude (ATT), subjective norm (SJN), and perceived behavioral control (PBC). Using an explanatory sequential mixed-methods design, survey data from 854 Thai retail consumers were analyzed through Structural Equation Modeling (SEM), followed by in-depth interviews. Results show that health and environmental claims significantly enhance ELQ, while ethical claims have limited impact due to perceived ambiguity. ELQ strongly predicts ATT, SJN, and PBC, with ATT emerging as the dominant mediator of SPI. Qualitative insights reveal that trust, emotional resonance, and social cues shape consumer interpretations of label content. This study contributes by extending TPB with content-specific informational cues: health claims that emphasize nutrition, wellness, and trust; ethical claims that address fairness, animal welfare, and social responsibility; and environmental claims that highlight carbon footprint, recyclability, and ecological impact. By positioning ELQ as a bridge between rational evaluation and affective responses, the study advances theory while providing practical guidance for policymakers and retailers to promote sustainable consumption in physical retail contexts.