Hydration, mood, and cognition in primary aged school children in the United Kingdom

• Published in: Proceedings of the Nutrition Society 2024-11, Vol.83 (OCE4)
• Main Authors: Roberts, CA, Boak, K, McCullogh, N, Haskell-Ramsay, C, James, LJ, Green, BP, Tempest, GD, Buce-Martin, C, Rumbold, PLS
• Format: Article
• Language: English
• Subjects: Body mass index; Body size; Boredom; Children; Cognition; Cognition & reasoning; Dehydration; Drinking water; Fluid intake; Food intake; Hunger; Hydration; Long term memory; Meals; Memory; Memory tasks; Mental performance; Mood; Performance assessment; Specific gravity; Thirst; Urine; Water intake; Water intakes
• ISSN: 0029-6651; 1475-2719
• DOI: 10.1017/S002966512400716X

Children are at increased risk of dehydration(1–3), which can adversely impact cognition and mood(4–6). Many children begin their school day dehydrated and fail to replenish fluids adequately throughout the day(7–11), however, these findings have not been confirmed using objective measures of hydration(12,13). This study aimed to confirm hydration status of primary school-aged children across the school day using objective hydration assessments and to examine if changes in hydration are associated with cognition and mood. Thirty children (mean age 9.4 ± 0.5 years old, stature 1.4 ± 0.5m, body mass 36.5 ± 4.2kg, and body mass index 18.9 ± 1.7 kg/m2) were recruited from a local primary school. Food and fluid intake were tracked via nutritional analysis of photographs. Urine osmolality (Uosm), serum osmolality (Sosm), urine specific gravity (USG) and self-reported urine colour (Ucol) were assessed at first void (Uosm only) or the start (9:00) and end (16:00) of the school day. Children’s self-reported mood were obtained via Visual Analogue Scales(100mm) (9:00, 10:30, 13:30, 16:00). Children completed cognitive assessments using the Computerised Mental Performance Assessment System (15:3016:00). Mean total water intake was 759.9 ± 240.7 mL. Children consumed more fluid at mealtimes than from water bottle (Mean Difference (MD) 154.3mL, t(29) = -5.763, p1.030) increased from the start (17%) to the end of school (40%). A series of ANOVAs from the start to the end of the day showed feelings of boredom, hunger, tiredness, and thirst increased, and focus, and happiness decreased (p’s