Unveiling the impact of health star ratings: Subjective nutrition knowledge as a moderator of consumer responses to unhealthy foods

The present research demonstrates that a Health Star Rating (HSR), one type of interpretive label, can enhance consumer responses among individuals with low subjective nutrition knowledge (SNK). Across three experiments, including a qualitative follow-up, we show that voluntarily adopted HSRs increase preference and purchase intention—even for products with low health ratings—by fostering favorable brand inferences rooted in perceived transparency, particularly among individuals with lower SNK. This work contributes to the food labeling literature by identifying which consumers are most likely to benefit from HSRs on unhealthy items and extends attribution theory by illustrating how voluntary disclosure can enhance brand evaluations. Practically, our findings suggest that, when paired with consumer education, voluntary interpretive labeling—such as the HSR—can support informed decision-making, guide policymakers in promoting non-mandatory labeling systems, and enhance brand perceptions for food companies.