Habitual total water intake and dimensions of mood in healthy young women

•We examined total dietary water intake and mood in 120 healthy young women.•We accounted for known mood influences (macronutrients, exercise and caffeine).•Water intake predicted total mood disturbance beyond known mood influencers.•Habitual low water intake volumes corresponded with adverse mood states.•Habitual high water intake might optimize daily mood state. Acute negative and positive mood states have been linked with the development of undesirable and desirable health outcomes, respectively. Numerous factors acutely influence mood state, including exercise, caffeine ingestion, and macronutrient intake, but the influence of habitual total water intake remains unknown. The purpose of this study was to observe relationships between habitual water intake and mood. One hundred twenty healthy females (mean ± SD; age = 20 ± 2 y, BMI = 22.9 ± 3.5 kg⋅m−2 ) recorded all food and fluids consumed for 5 consecutive days. Investigators utilized dietary analysis software to determine Total Water Intake (TWI; total water content in foods and fluids), caffeine, and macronutrient consumption (i.e. protein, carbohydrate, fat). On days 3 and 4, participants completed the Profile of Mood State (POMS) questionnaire, which examined tension, depression, anger, vigor, and confusion, plus an aggregate measure of Total Mood Disturbance (TMD). For comparison of mood, data were separated into three even groups (n = 40 each) based on TWI: low (LOW; 1.51 ± 0.27 L/d), moderate (MOD; 2.25 ± 0.19 L/d), and high (HIGH; 3.13 ± 0.54 L/d). Regression analysis was performed to determine continuous relationships between measured variables. Group differences (p