Background: In childhood, inadequate fluid intakes can lead on the short term, to reduced physical and cognitive performances. However, few data are available on the fluid intake among schoolchildren in Belgium. The main aim of this study is to evaluate total fluid intake provided by different types of beverages in a sample of Belgian schoolchildren, in order to assess the percentage of individuals complying with the European Food Safety Authority recommendations for total fluid intake. A secondary aim was to characterize the study population in terms of determinants of the total fluid intake requirements.
Methods: A child friendly "fluids and liquid food" diary was used to prospectively record the volume and frequency of beverage consumption over 7 days from 1045 schoolchildren. This diary also recorded the practice of physical activity. An adequate fluid intake was defined as an intake ≥ 75% of the age-specific adequate intake recommended by the EFSA.
Results: The median (P25-P75) of habitual daily fluid intake was 864 (608-1104) ml/day, with 355 (194-579) coming from drinking water. This habitual daily fluid intake varied significantly among the three investigated EFSA groups (girls and boys aged from 8 years, girls from 9 to 13 and boys from 9 to 13), except for the drinking water (P = 0.906). The highest medians of fruit juice, sugar-sweetened beverages and milk and derivatives were found among boys of 9-13. Only 9.5% of the children had an adequate fluid intake, with a value of 19.2% among the 8 years old girls and boys, 7.0% among girls of 9-13 and 8.4% among boys of 9-13. In the whole sample, 27.7% of the children declared to drink less than 3-4x/day, 56% drunk water less than 2x/day and 7.7% drunk no water at all. Every day, 27.1% and 34.1% of the children drank respectively one fruit juice and one sugar-sweetened beverage.
Conclusion: Belgian schoolchildren have an inadequate total fluid intake. Given the potential health consequences, interventions involving parents and school environment to promote water consumption seem pertinent.