Disparities in plain, tap and bottled water consumption among US adults: National Health and Nutrition Examination Survey (NHANES) 2007-2014

Objective: Differences in bottled v. tap water intake may provide insights into health disparities, like risk of dental caries and inadequate hydration. We examined differences in plain, tap and bottled water consumption among US adults by sociodemographic characteristics. Design: Cross-sectional analysis. We used 24 h dietary recall data to test differences in percentage consuming the water sources and mean intake between groups using Wald tests and multiple logistic and linear regression models. Setting: National Health and Nutrition Examination Survey (NHANES), 2007-2014. Subjects: A nationally representative sample of 20 676 adults aged >= 20 years. Results: In 2011-2014, 81.4 (se 0.6) % of adults drank plain water (sum of tap and bottled), 55.2 (se 1.4) % drank tap water and 33.4 (se 1.4) % drank bottled water on a given day. Adjusting for covariates, non-Hispanic (NH) Black and Hispanic adults had 0.44 (95 % CI 0.37, 0.53) and 0.55 (95 % CI 0.45, 0.66) times the odds of consuming tap water, and consumed B=-330 (SE 45) ml and B=-180 (SE 45) ml less tap water than NH White adults, respectively. NH Black, Hispanic and adults born outside the fifty US states or Washington, DC had 2.20 (95 % CI 1.79, 2.69), 2.37 (95 % CI 1.91, 2.94) and 1.46 (95 % CI 1.19, 1.79) times the odds of consuming bottled water than their NH White and US-born counterparts. In 2007-2010, water filtration was associated with higher odds of drinking plain and tap water. Conclusions: While most US adults consumed plain water, the source (i.e. tap or bottled) and amount differed by race/Hispanic origin, nativity status and education. Water filters may increase tap water consumption.