title: Evaluation of seasonality on total water intake, water loss and water balance in the general population in Greece.
abstract: BACKGROUND
  Water balance is achieved when water intake from solid and fluid foods and drinking water meets water losses, mainly in sweat, urine and faeces. Seasonality, particularly in Mediterranean countries that have a hot summer, may affect water loss and consequently water balance. Water balance has not been estimated before on a population level and the effect of seasonality has not been evaluated. The present study aimed to compare water balance, intake and loss in summer and winter in a sample of the general population in Greece.
  
  
  METHODS
  The Water Balance Questionnaire (WBQ) was used to evaluate water balance, estimating water intake and loss in summer (n = 480) and in winter (n = 412) on a stratified sample of the general population in Athens, Greece.
  
  
  RESULTS
  In winter, mean (SD) water balance was -63 (1478) mL/day(-1) , mean (SD)water intake was 2892 (987) mL/day(-1) and mean (quartile range) water loss was 2637 (1810-3922) mL/day(-1) . In summer, mean (SD) water balance was -58 (2150) mL/day(-1) , mean (SD) water intake was 3875 (1373) mL/day(-1) and mean (quartile range) water loss was 3635 (2365-5258) mL/day(-1) . Water balance did not differ between summer and winter (P = 0.96); however, the data distribution was different; in summer, approximately 8% more participants were falling in the low and high water balance categories. Differences in water intake from different sources were identified (P < 0.05).
  
  
  CONCLUSIONS
  Water balance in summer and winter was not different. However, water intake and loss were approximately 40% higher in summer than in winter. More people were falling in the low and high water balance categories in summer when comparing the distribution on water balance in winter.
authors.affiliation: Unit of Human Nutrition, Department of Food Science and Technology, Agricultural University of Athens, Athens, Greece.
authors.forename: O
authors.initials: O
authors.lastname: Malisova
authors.forename: V
authors.initials: V
authors.lastname: Bountziouka
authors.forename: D Β
authors.initials: DΒ
authors.lastname: Panagiotakos
authors.forename: A
authors.initials: A
authors.lastname: Zampelas
authors.forename: M
authors.initials: M
authors.lastname: Kapsokefalou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001826:Body Fluids / Q000378:metabolism*; D004326:Drinking; D005260:Female; D006115:Greece; D006801:Humans; D008297:Male; D008875:Middle Aged; D012621:Seasons; D011795:Surveys and Questionnaires; D013696:Temperature; D014867:Water / Q000378:metabolism*; D014882:Water-Electrolyte Balance; D055815:Young Adult
chemical_list: D014867:Water