Dietary and Health Correlates of Sweetened Beverage Intake: Sources of Variability in the National Health and Nutrition Examination Survey (NHANES)

Recent studies using data from the National Health and Nutrition Examination Survey (NHANES) have used inconsistent approaches to identify and categorize beverages, especially those containing low-calorie sweeteners (LCS), also referred to as low-calorie sweetened beverages (LCSBs). Herein, we investigate the approaches used to identify and categorize LCSBs in recent analyses of NHANES data. We reviewed published studies examining LCS consumption in relation to dietary and health outcomes and extracted the methods used to categorize LCS as reported by the authors of each study. We then examined the extent to which these approaches reliably identified LCSBs using the Internet Archive Wayback Machine to examine beverage ingredients lists across three NHANES cycles (2011-2016). None of the four general strategies used appeared to include all LCSBs while also excluding all beverages that did not contain LCS. In some cases, the type of sweetener in the beverage consumed could not be clearly determined; we found 9, 16, and 18 of such "mixed" beverage identifiers in the periods 2011-2012, 2013-2014, and 2015-2016, respectively. Then, to illustrate how heterogeneity in beverage categorization may impact the outcomes of published analyses, we compared results of a previously published analysis with outcomes when "mixed" beverages were grouped either all as LCSBs or all as sugary beverages. Our results suggest that caution is warranted in design and interpretation of studies using NHANES data to examine dietary and health correlates of sweetened beverage intake.