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Water as an essential nutrient: the physiological basis of hydration

European Journal of Clinical Nutrition volume 64, pages 115–123 (2010)Cite this article

Abstract

How much water we really need depends on water functions and the mechanisms of daily water balance regulation. The aim of this review is to describe the physiology of water balance and consequently to highlight the new recommendations with regard to water requirements. Water has numerous roles in the human body. It acts as a building material; as a solvent, reaction medium and reactant; as a carrier for nutrients and waste products; in thermoregulation; and as a lubricant and shock absorber. The regulation of water balance is very precise, as a loss of 1% of body water is usually compensated within 24 h. Both water intake and water losses are controlled to reach water balance. Minute changes in plasma osmolarity are the main factors that trigger these homeostatic mechanisms. Healthy adults regulate water balance with precision, but young infants and elderly people are at greater risk of dehydration. Dehydration can affect consciousness and can induce speech incoherence, extremity weakness, hypotonia of ocular globes, orthostatic hypotension and tachycardia. Human water requirements are not based on a minimal intake because it might lead to a water deficit due to numerous factors that modify water needs (climate, physical activity, diet and so on). Water needs are based on experimentally derived intake levels that are expected to meet the nutritional adequacy of a healthy population. The regulation of water balance is essential for the maintenance of health and life. On an average, a sedentary adult should drink 1.5 l of water per day, as water is the only liquid nutrient that is really essential for body hydration.

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References

  • Armstrong LE (2005). Hydration assessment techniques. Nut Rev 63, S40–S54.

    Article  Google Scholar 

  • Armstrong LE, Soto JA, Hacker Jr FT, Casa DJ, Kavouras SA, Maresh CM (1998). Urinary indices during dehydration, exercise, and rehydration. Int J Sport Nutr 8, 345–355.

    Article  CAS  PubMed  Google Scholar 

  • D’Anei KE, Constant F, Rosenberg IH (2006). Hydration and cognitive function in children. Nutr Rev 64, 457–464.

    Article  Google Scholar 

  • Dietary Reference Intakes (2006). The Essential Guide to Nutrients Requirements. Institute of Medicine of the National Academies: Washington DC, 543 pp.

  • EFSA (2008). Draft dietary reference values for water. Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies, (agreed on 11 April 2008 for release for public consultation).

  • Ellis KJ, Wong WW (1998). Human hydrometry: comparison of multifrequency bioelectrical impedance with H20 and bromine dilution. J Appl Physiol 85, 1056–1062.

    Article  CAS  PubMed  Google Scholar 

  • Francesconi RP, Hubbard RW, Szlyk PC, Schnakenberg D, Carlson D, Leva N et al. (1987). Urinary and hematologic indexes of hypohydration. J Appl Physiol 62, 1271–1276.

    Article  CAS  PubMed  Google Scholar 

  • Ganong WF (2005). Review of Medical Physiology, 22nd edn, LANGE-Science: New York.

    Google Scholar 

  • Gorelick MH, Shaw KN, Murphy KO (1997). Validity and reliability of clinical signs in the diagnosis of dehydration in children. Pediatrics 99, E6.

    Article  CAS  PubMed  Google Scholar 

  • Grandjean AC, Campbell SM (2004). Hydration: Fluids for Life. A monograph by the North American Branch of the International Life Science Institute. ILSI North America: Washington DC.

    Google Scholar 

  • Grandjean AC, Reimers CJ, Buyckx ME (2003). Hydration: issues for the 21st century. Nutr Rev 61, 261–271.

    Article  PubMed  Google Scholar 

  • Gudivaka R, Schoeller DA, Kushner RF, Bolt MJG (1999). Single and multifrequency models for bioelectrical impedance analysis of body water compartments. J Appl Physiol 87, 1087–1096.

    Article  CAS  PubMed  Google Scholar 

  • Häussinger D (1996). The role of cellular hydration in the regulation of cell function. Biochem J 313, 697–710.

    Article  PubMed  PubMed Central  Google Scholar 

  • Lang F, Waldegger S (1997). Regulating cell volume. Am Scientist 85, 456–463.

    Google Scholar 

  • Lieberman HR (2007). Hydration and cognition: a critical review and recommendations for future research. J Am Coll Nutr 26 (Suppl 5), 555S–561S.

    Article  PubMed  Google Scholar 

  • Manz F, Wentz A, Sichert-Hellert W (2002). The most essential nutrient: defining the adequate intake of water. J Pediatr 141, 587–592.

    Article  PubMed  Google Scholar 

  • Mathie JR (2005). Second generation mixture theory equation for estimating intracellular water using bioimpedance spectroscopy. J Appl Physiol 99, 780–781.

    Article  Google Scholar 

  • Maughan RJ, Shirreffs SM, Watson P (2007). Exercise, heat, hydration, and the brain. J Am Coll Nutr 26 (Suppl 5), 604S–612S.

    Article  CAS  PubMed  Google Scholar 

  • Mayo Clinic (2008): http://www.mayoclinic.com/health/dehydration/DS00561/DSECTION=symptoms.

  • Mentes JC, Wakefield B, Culp K (2006). Use of a urine color chart to monitor hydration status in nursing home residents. Biol Res Nurs 7, 197–203.

    Article  PubMed  Google Scholar 

  • Montain SJ, Latzka WA, Sawka MN (1999). Fluid replacement recommendations for training in hot weather. Mil Med 164, 502–508.

    Article  CAS  PubMed  Google Scholar 

  • Murray B (2007). Hydration and physical performance. J Am Coll Nutr 26 (Suppl 5), 542S–548S.

    Article  PubMed  Google Scholar 

  • Oppliger RA, Magnes SA, Popowski LA, Gisolfi CV (2005). Accuracy of urine specific gravity and osmolality as indicators of hydration status. Int J Sport Nutr Exerc Metab 15, 236–251.

    Article  PubMed  Google Scholar 

  • Phillips PA, Rolls BJ, Ledingham JG, Forsling ML, Morton JJ, Crowe MJ et al. (1984). Reduced thirst after water deprivation in healthy elderly men. N Engl J Med 311, 753–759.

    Article  CAS  PubMed  Google Scholar 

  • Pialoux V, Mischler I, Mounier R, Gachon P, Ritz P, Coudert J et al. (2004). Effect of equilibrated hydration changes on total body water estimates by bioelectrical impedance analysis. Br J Nutr 91, 153–159.

    Article  CAS  PubMed  Google Scholar 

  • Ritz P (2001). Bioelectrical impedance analysis estimation of water compartments in elderly diseased patients: the source study. J Gerontol 56, M344–M348.

    Article  CAS  Google Scholar 

  • Ritz P, Berrut G (2005). The importance of good hydration for day-to-day health. Nutr Rev 63, S6–S13.

    Article  PubMed  Google Scholar 

  • Sawka MN (1992). Physiological consequences of hypohydration: exercise performance and thermoregulation. Med Sci Sports Exerc 24, 657–670.

    CAS  PubMed  Google Scholar 

  • Sawka MN, Cheuvront SN, Carter III R (2005). Human water needs. Nutr Rev 63, S30–S39.

    Article  PubMed  Google Scholar 

  • Shirreffs SM (2003). Markers of hydration status. Eur J Clin Nutr 57 (Suppl 2), S6–S9.

    Article  PubMed  Google Scholar 

  • Shirreffs SM (2005). The importance of good hydration for work and exercise performance. Nutr Rev 63, S14–S21.

    Article  PubMed  Google Scholar 

  • Szinnai G, Schachinger H, Arnaud MJ, Linder L, Keller U (2005). Effect of water deprivation on cognitive-motor performance in healthy men and women. Am J Physiol Regul Integr Comp Physiol 289, R275–R280.

    Article  CAS  PubMed  Google Scholar 

  • Thomas DR, Cote TR, Lawhorne L, Levenson SA, Rubestein LZ, Smith DA et al. (2008). Understanding clinical dehydration and its treatment. J Am Med Dir Assoc 9, 292–301.

    Article  PubMed  Google Scholar 

  • Wang ZM, Deurenberg P, Wang W, Pietrobelli A, Baumgartner RN, Heymsfield SB (1999). Hydration of fat-free body mass: a review and critique of a classic body-composition constant. Am J Clin Nutr 69, 833–841.

    Article  CAS  PubMed  Google Scholar 

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Authors and Affiliations

  1. Department of Physiology, University of Lausanne, Pully, Switzerland

    E Jéquier

  2. Nestl,

    F Constant

  3. é Waters, Paris, France

    F Constant

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  1. E Jéquier
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  2. F Constant
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Correspondence to E Jéquier.

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Jéquier, E., Constant, F. Water as an essential nutrient: the physiological basis of hydration. Eur J Clin Nutr 64, 115–123 (2010). https://doi.org/10.1038/ejcn.2009.111

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  • DOI: https://doi.org/10.1038/ejcn.2009.111

Keywords

  • water
  • hydration
  • dehydration
  • dietary requirements

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