The Multiple Ingredients Effect: The More Diverse (Un)Healthy Ingredients, the More (Un)Healthy the Food

Background: Although previous research has demonstrated that ingredient information plays a significant role in consumers' healthier food choices, none of the research has investigated how the number of ingredients (ie, single vs multiple) influences consumer perceptions of food healthiness. However, this research argues that consumers have lay belief that the greater the number of (un)healthy ingredients in food, the more (un)healthy the food is perceived and they rely on the lay belief when judging food healthiness. Thus, this paper proposes and examines the multiple ingredients effect that people make inferences about food (un)healthiness based on the diversity of (un)healthy ingredients. Methods and Results: Four studies test our hypotheses using ANOVAs and regression analyses. Study 1 examines that people indicate a higher perception of food unhealthiness when the number of unhealthy ingredients is presented as multiple rather than single. Study 2 replicates the multiple ingredients effect in the healthy food domain and eliminates an alternative explanation based on the subadditivity effect. Study 3 also finds that the difference in food healthiness perception between people who have high and low health consciousness is driven by the salience of each ingredient. Finally, Study 4 identifies the evaluability of the nutritional value as a boundary condition for our effect in an AI-based self-service context. Conclusion: The current research demonstrates the multiple ingredients effect that people perceive higher food (un)healthiness when the number of (un)healthy ingredients is greater although nutritional information is identically presented. Moreover, this effect is moderated by the extent to which people are conscious of health-related issues. This finding is because ingredient information is highly accessible and salient for health-conscious people.