PURPOSE: This study aimed to examine the psychological factors (knowledge, barriers and facilitators) that can contribute to hydration-related behaviors (i.e., fluid intake) in the general population and how these relate to physical health. METHODS: A structured survey was developed to examine the links between hydration knowledge (29 items), attitudes about hydration (80 items), and fluid intake behavior (8 items) among US adults. Survey data from Phase 1 (n =301, US adults) psychometrically evaluated the items via item analysis (knowledge and fluid behavior) and factor analysis (attitudes). Phase 2 survey data (n =389, US adults and college students) refined and validated the new 16-item hydration knowledge measure, 4-item fluid intake behavior index, and 18-item attitude measure (barriers and facilitators of hydration-related behaviors) alongside indices of physical health (BMI and exercise behaviors). RESULTS: Participants had a moderate level of hydration knowledge (Phase 1: 10.91 ± 3.10; Phase 2: 10.87 ± 2.47). A five-factor measure of attitudes which assessed both facilitators (social pressure and attention to monitoring) and barriers (lack of effort, physical barriers and lack of a fluid container) to hydration demonstrated strong internal consistency (αs from 0.75 to 0.90). Attitudes about hydration-most notably barriers to hydration-were associated with indicators of health and with fluid intake behaviors, whereas hydration knowledge was not. CONCLUSIONS: Increasing hydration knowledge may be necessary for people who hold inaccurate information about hydration, but attitudes about hydration are likely to have a larger impact on fluid intake behaviors and health-related outcomes.
