Tap water avoidance and the impact on food insecurity is an understudied subject. The purpose of this research was to 1) test how water avoidance covaries with food insecurity, 2) examine how the probability of food insecurity has changed by tap water avoidance between 2005-2018 in the US, and 3) to examine how the relationship between water avoidance and food insecurity differs by income and housing status. Data from this study was obtained from seven cycles of the National Health and Nutritional Examination Survey (NHANES) between 2005 and 2018. Food insecurity was measured in NHANES using a series of validated questions. The measurement of tap water avoidance relied on a proxy of water insecurity measured by NHANES (i.e., if a participant reported not drinking their tap water). Water insecurity was also measured by two other variables in NHANES: any tap water consumption on a given day and exclusive bottled water consumption on a given day. Statistical analysis for tap water avoidance and odds of food insecurity used adjusted logistic regression models. Food insecurity over time by income and housing status used predicted probabilities and plotted using marginal standardization.
Results showed that 15.8% of respondents were tap water avoiders, and 47.1% did not drink any tap water on a given day, and 27.9% drank exclusively bottled water. Adults who avoided tap water had a 21% higher odds of any food insecurity compared to those who drank tap water (odds ratio [OR]=1.21; 95% CI: 1.09-1.34). Adults who did not drink any tap water on a given day had a 30% higher odds of any food insecurity compared to adults who drank at least some tap water (OR=1.30; 95% CI: 1.19-1.42). The probability of food insecurity doubled between 2005-2018 and was higher among tap water avoiders. For the third aim of this study, food insecurity was higher among tap water avoiders at all income levels. And finally, food insecurity was higher among tap water avoiders for both renters and homeowners compared to those to drank tap water.
Study strengths: NHANES uses a multi-stage, probability sampling design to create a nationally representative sample. This study also measured tap water avoidance in different ways, all which produced consistent results. Food security was measured using the well-validated US Food Security Survey Module. Finally, analyzing seven cycles of NHANES data strengthened this study by providing additional evidence that tap water avoidance is associated with food insecurity over time.
Study limitations: One limitation of this study was the use of proxies to measure water insecurity. Additionally, this study did control for multiple confounding socioeconomic variables known to cause water and food insecurity, but it is possible that others exist. Finally, NHANES is a cross-sectional survey; future research should assess different study designs that may assess causality.
What this means for your practice: The findings from study have important public health implications that food insecurity may be intensified among those who experience water insecurity. As appropriate, communicating to families that tap water is safe, affordable, and healthy beverage choice may facilitate healthier food and beverage choices. There may be opportunities as well to advocate for access to a safe water supply in some geographic areas. If families have questions about the safety of tap water, you can refer them to the Environmental Protection Agency for more information.
Original citation: Rosinger AY, Bethancourt HJ, Young SL. Tap water avoidance is associated
with lower food security in the US: Evidence from NHANES 2005-2018, Journal of the Academy of Nutrition and Dietetics (2022), doi: https://doi.org/10.1016/j.jand.2022.07.011.