(P19-017-24) Water Intake and Hydration Status in Children

Objectives: Underhydration is a common occurrence in children due to a low perception of thirst. The current study assessed the relationship between children’s water intake and 24-hour urinary hydration biomarkers in a large US-based sample.

Methods: We collected data on 729 healthy children (3-13 y; 46% female) from Northwest Arkansas and Phoenix, Arizona. Total water intake (TWI) from beverages and food was assessed based on a two-day food and beverage diary. Adequate intake of TWI was dichotomized based on meet vs. do not meet National Academy of Medicine (NAM) TWI guidelines. Hydration biomarkers, including urine osmolality (UOsm), urine specific gravity (USG), and urine color, were assessed from urine samples collected over 24 hours, during the 2^nd day of the two-day dietary records.

Results: Over half of the children (57.7%) did not meet the NAM TWI guidelines. Over one-third of children were underhydrated based on 24-h UOsm (≥800 mmol/kg, 37%). Over two-thirds of children were not optimally hydrated ( >500 mmol/kg, 77%). Children not meeting NAM TWI guidelines had a 1.5 times higher risk of being underhydrated (24-h UOsm ≥800 mmol/kg). Children who consumed less than three cups of plain water intake (PWI) per day (55.7%) had a 2.4 times higher risk of not meeting the NAM TWI guidelines and a 1.4 times higher risk of being underhydrated. TWI was significantly associated with PWI, sugar-sweetened beverages, TWI from food, total energy intake, sodium intake, and ambient temperature (F_13,681 = 436, P < 0.0001; R² = 0.89). Twenty-four-hour UOsm was significantly associated with PWI, sodium intake, energy intake, and sex (F_13,681 = 3.4, R² = 0.06; P</em> < 0.0001).

Conclusions: These results suggest the majority of children are underhydrated or fail to meet optimal hydration standards as a result of low TWI.

Funding Sources: Danone Research