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. SPONSORSHIP: Funding for the DONALD Study and its analyses is provided by the Ministry of Innovation, Science, Research and Technology of the State of North Rhine-Westphalia, Germany. PMID: 17311062 [PubMed – indexed for MEDLINE