The association between hydration status and total fluid intake in healthy children and adolescents.

Background: Children 10-20 years old in the US have suboptimal hydration status. Hydration is best assessed using an objective marker, such as urine specific gravity (USG) from a 24-h urine collection. There are limited studies associating hydration from an objective marker with intake assessed from 24-h recalls in children. The objective of the study was to evaluate which foods or beverages are significantly associated with an objective marker of hydration (USG) in a sample of children and adolescents.

Methods: Intake was assessed from three 24-h dietary recalls and analyzed using the Nutrition Data System for Research (NDSR). Hydration status was objectively measured using USG via 24-h urine collection. Associations were assessed with logistic regressions.

Results: A total of 68 children and adolescents were recruited (50% females). Average overall USG score was 1.020 ± 0.011 uG with 39.7% categorized as dehydrated. After adjusting for age and sex, fruit juice (1.009, 95% CI: 1.001, 1.018) and all beverages (1.001, 95% CI: 1.000, 1.002) were significantly associated with higher odds of being euhydrated.

Conclusions: The main predictors of hydration were fruit juice and all beverages intake. Future research should be conducted to explore differences in dietary patterns in a larger, more generalizable sample.

Impact: Findings showed that the main predictors of hydration were water and fruit juice intake in children and water intake in adolescents in southern Florida. This is the first study to examine which type of beverages and foods are associated with USG, an objective marker of hydration status, in US children and adolescents. Provides further insight into the use of objective markers to assess hydration status, while providing data to assist epidemiological studies that may have limited resources to examine beverages and foods that contribute to hydration.