Defining "Carrier Foods" - A Novel Basis for Evaluating Indirect Contributions to Diet Quality

Efforts to improve dietary patterns often focus on the nutritional composition and associated health effects of individual foods in isolation. This reductionist type of approach has been traditionally applied across nutrition science, leading to a weakened understanding of the complex interplay of how food affects human health. Emerging evidence suggests that many foods may exert indirect effects on overall diet quality by acting as a vehicle that increases co-consumption of other foods. Thus, the term "carrier food" is intended to describe such foods that, regardless of its direct effect (i.e. nutritional contribution), indirectly impacts diet quality by serving as a vehicle for increasing co-consumption of other foods or food groups, during a snacking or eating occasion. In this context, the "companion food" is consumed due to its relationship with consumption of the carrier food. Carrier foods can be classified into four types - positive, offset, gateway, and reverse - each exerting a unique impact on overall diet quality. This editorial defines and contextualizes the term carrier food, explores examples and methods from existing nutrition research, and outlines implications for public health messaging, food formulation, and dietary assessment. By shifting focus from individual nutrients to patterns of co-consumption, the concept of a carrier food offers a more nuanced and actionable approach to dietary assessment and intervention. As food and nutrition science continues to evolve, integrating this term into research, policy, and practice may help better align nutritional recommendations with real-world eating behavior.