Perspective: Chaos in a Bottle-A Critical Evaluation of Beverage Categorization in Nutrition Research.

Beverage consumption is an important contributor to total daily calorie intake among children and adolescents. While associations between excess calories from beverages and development of obesity are well established, a standardized approach for beverage categorization does not exist. As a result, there is marked heterogeneity in assessment and categorization of beverage intake across studies. The purpose of this article is to critically review beverage categorization in recent (published since 2010) observational studies that evaluated beverage intake in relation to weight/adiposity in US youth, and to put forth an initial proposal for a standardized beverage classification system. Standardized beverage classification is critical to ensure transparency in nutrition science research and facilitate comparison of findings across studies. A systematic literature search identified 37 eligible studies, across which beverage categorization varied considerably. The most heterogeneity was observed for categorization of "sugar-sweetened beverages" and the greatest consistency was observed for categorization of 100% juices. This review provides an evidence-based starting point for urgently needed, collaborative work to determine priorities for beverage categorization and leverage existing standards of identity in order to create and disseminate a standardized beverage classification system. A standardized approach will inform meaningful assessment of beverage consumption in research studies and facilitate impactful translation of research findings into public health nutrition policy.