Relation between hydration status in children and their dietary profile -- results from the DONALD study

Objective: To describe associations between hydration status and dietary behaviour in children, as current research indicates that hydration status is influenced by nutrition vice versa, hydration status may influence dietary behaviour. Design: Cross-sectional analyses of data from the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, (DONALD) using 24-h urine samples to determine the hydration status and 3-day weighed food records to describe the dietary profile of the children. Setting: Secondary analyses of data from an observational study. Subjects: A group of 4-11 year old children living in Dortmund, Germany; N=717. Methods: Hydration status was determined by calculating the 'free water reserve', using analyses of the 24-h urine samples. Nutrient intake per day was calculated from the 3-day weighed food records. Children were categorized into groups of hydration status and analysed for significant differences in their dietary profile. Results: Children in the highest group of the hydration status had significant higher total water intake, lower energy density of the diet and a lower proportion of metabolic water compared to children in the lowest group of the hydration status. In addition, analyses showed -- although not significant in all subgroups -- that better hydrated children consumed more water from beverages and water-supplying foods and less energy from fat. Conclusions: Euhydrated children, that are children in the highest group of hydration status, had a more preferable dietary profile than children at risk of insufficient hydration.