Hydration Knowledge, Water Consumption, and Attitudes Toward Drinking Water Quality Among Adults in Romania: A Cross-Sectional Study

Background/Objectives: Adequate hydration is essential for health; however, water consumption behaviors are influenced not only by physiological needs but also by hydration knowledge and perceptions of drinking water quality. Empirical evidence examining these factors in Eastern European populations remains limited. This study aimed to assess hydration knowledge, water consumption patterns, and attitudes toward drinking water quality among adults in Romania, and to examine their associations with daily water intake and water source preferences. Methods: A cross-sectional study was conducted between November 2024 and November 2025 among adults residing in Romania. Data were collected from 165 participants using an anonymous, self-developed, paper-based questionnaire administered in person to adult patients attending routine visits in four primary care clinics in Arad, Romania, using a convenience sampling approach. The questionnaire assessed sociodemographic characteristics, hydration knowledge, water consumption behaviors, and attitudes toward drinking water quality. Descriptive statistics, chi-square tests, correlation analyses, and multivariable linear and logistic regression models were applied to identify factors associated with daily water intake, adequate hydration (≥2 L/day), and bottled water consumption. Results: Hydration knowledge was moderate overall and was significantly associated with education level and gender. Higher hydration knowledge was positively correlated with daily water intake (r = 0.21, p = 0.006) and was independently associated with higher intake and adequate hydration (OR = 1.28, 95% CI: 1.10–1.49; p = 0.002). Greater trust in tap water was also positively associated with daily intake (r = 0.27, p = 0.001) and adequate hydration (OR = 1.31, 95% CI: 1.12–1.54; p < 0.001). Lower trust in tap water and stronger beliefs regarding bottled water were significant predictors of bottled water use as the primary drinking water source. Education level emerged as a consistent predictor across multiple hydration-related outcomes. Conclusions: Hydration knowledge and perceptions of drinking water quality are key, modifiable factors associated with water consumption behaviors. Educational strategies integrated into primary care and transparent communication regarding tap water safety may support adequate and sustainable hydration among adults.