French children start their school day with a hydration deficit.
OBJECTIVE
Fluid requirements of children vary as a function of gender and age. To our knowledge, there is very little literature on the hydration status of French children. We assessed the morning hydration status in a large sample of 529 French schoolchildren aged 9-11 years.


METHODS
Recruited children completed a questionnaire on fluid and food intake at breakfast and collected a urine sample the very same day after breakfast. Breakfast food and fluid nutritional composition was analyzed and urine osmolality was measured using a cryoscopic osmometer.


RESULTS
More than a third of the children had a urine osmolality between 801 and 1,000 mosm/kg while 22.7% had a urine osmolality over 1,000 mosm/kg. This was more frequent in boys than in girls (p < 0.001). A majority of children (73.5%) drank less than 400 ml at breakfast. Total water intake at breakfast was significantly and inversely correlated with high osmolality values.


CONCLUSIONS
Almost two thirds of the children in this large cohort had evidence of a hydration deficit when they went to school in the morning, despite breakfast intake. Children's fluid intake at breakfast does not suffice to maintain an adequate hydration status for the whole morning.
Service Endocrinologie-Diabétologie-Nutrition, Hôpital Sud, CHU de Rennes, France.
Fabrice
F
Bonnet
Eve M
EM
Lepicard
Lucas
L
Cathrin
Catherine
C
Letellier
Florence
F
Constant
Nasrine
N
Hawili
Gérard
G
Friedlander
D002648:Child; D002664:Child Nutritional Physiological Phenomena; D015331:Cohort Studies; D004326:Drinking; D060766:Drinking Water; D002149:Energy Intake; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D044342:Malnutrition / Q000453:epidemiology* / Q000503:physiopathology; D015596:Nutrition Assessment; D009751:Nutritional Requirements; D009994:Osmolar Concentration; D012574:Schools; D014556:Urine / Q000737:chemistry; D044465:White People
D060766:Drinking Water