Tap Water Avoidance Is Associated with Lower Food Security in the United States: Evidence from NHANES 2005-2018

Background: Food insecurity has profound nutritional and public health consequences. Water insecurity may exacerbate food insecurity, yet little is known about the association between water and food insecurity in the United States or other high-income countries. Objective: This study aimed to estimate how tap water avoidance, a proxy of water insecurity, covaries with food insecurity; examine how the probability of food insecurity changed by tap water avoidance between 2005 and 2018; and test how the association between tap water avoidance and food insecurity differed across income and housing statuses. Design: This was a secondary analysis of the cross-sectional 2005-2018 National Health and Nutrition Examination Survey. Participants/setting: Participants were 31,390 US adults 20 years and older. Main outcome measures: The main outcome was food insecurity, using the US Food Security Survey Module. Statistical analyses: Adjusted logistic regression models estimated how tap water avoidance was associated with the odds of food insecurity. Predicted probabilities of food insecurity over time and by income and housing status were plotted using marginal standardization. Results: Adults who avoided tap water had 21% higher odds (95% CI 1.09 to 1.34) of food insecurity compared with those who drank tap water. The probability of any food insecurity doubled between 2005-2006 and 2017-2018 and was consistently higher for tap water avoiders. Food insecurity decreased across both tap water drinkers and avoiders as income increased, but was higher among tap water avoiders at all income levels. Likewise, food insecurity was higher among renters than among homeowners but was higher among tap water avoiders in both housing groups. Conclusions: Tap water avoidance is positively associated with food insecurity in the United States, and both insecurities have increased over time. Efforts to mitigate food insecurity should simultaneously address water insecurity issues, including tap water availability and quality, as these may be a modifiable contributors to food insecurity.