(P33-01-26) Lumping vs. Splitting Nutrients, Foods and Diet Patterns in Nutrition Research: Science Dialogue of Origins, Uses and Knowledge Gaps

Objectives: The practices of lumping together and splitting apart foods, nutrients, and diet patterns shape the interpretation of nutritional evidence and guidance. We aimed to discuss the inherent complexity of ‘lumping’ and ‘splitting’ decisions in nutrition research.

Methods: We held an in-person colloquium in December 2024, where we utilized dialogue mapping to summarize the discussion in real-time. Knowledgeable early-career researchers explored the contexts for lumping and splitting foods, nutrients, and diet patterns with the goal of beginning a conversation among the scientific community on the topic.

Results: A ‘dialogue map’ was produced to visualize the discussion, represented by nodes and arrows. Nodes were categorized by type to represent ideas, questions, supporting arguments, disagreements, notes, and decisions. Arrows connect these nodes to reflect how the discussion evolved. Six key themes emerged when discussing when to lump and/or split foods, nutrients, and diet patterns: definitions and history, population heterogeneity, consumer behavior, policy and public health messaging, frameworks and categorization, and measurements and methods. The overall discussion illustrated how the rationale for lumping or splitting often diverges based on the purpose of the categorization (e.g., mechanisms, health outcomes, public health messaging, and food labeling), as well as scientific data availability and the intended audience.

Conclusions: Panelists emphasized that lumping and splitting are not inherently right or wrong, nor are they inherently a binary approach; rather, the appropriateness to lump or split depends on the purpose of the analysis, public health message, or evidence-based decision making. Future work is needed to operationalize lumping and splitting decisions in the field of nutrition science, and to enhance transparency in the rationale of lumping and splitting decisions. Our work initiates the conversation about this ambiguity in lumping and splitting practices in nutrition research.

Funding Sources: Pork Checkoff