Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies, (agreed on 11 April 2008 for release for public consultation).Įllis KJ, Wong WW (1998). Draft dietary reference values for water. Institute of Medicine of the National Academies: Washington DC, 543 pp.ĮFSA (2008). The Essential Guide to Nutrients Requirements. Hydration and cognitive function in children. Int J Sport Nutr 8, 345–355.ĭ’Anei KE, Constant F, Rosenberg IH (2006). Urinary indices during dehydration, exercise, and rehydration. Nut Rev 63, S40–S54.Īrmstrong LE, Soto JA, Hacker Jr FT, Casa DJ, Kavouras SA, Maresh CM (1998). 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.Īrmstrong LE (2005). The regulation of water balance is essential for the maintenance of health and life. Water needs are based on experimentally derived intake levels that are expected to meet the nutritional adequacy of a healthy population. 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). Dehydration can affect consciousness and can induce speech incoherence, extremity weakness, hypotonia of ocular globes, orthostatic hypotension and tachycardia.

Healthy adults regulate water balance with precision, but young infants and elderly people are at greater risk of dehydration. Minute changes in plasma osmolarity are the main factors that trigger these homeostatic mechanisms. Both water intake and water losses are controlled to reach water balance. The regulation of water balance is very precise, as a loss of 1% of body water is usually compensated within 24 h. 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. Water has numerous roles in the human body. 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. How much water we really need depends on water functions and the mechanisms of daily water balance regulation.

Body doesn t absorb water