The recommended daily amount of drinking water for humans varies.[1] It depends on activity, age, health, and environment. In the United States, the Adequate Intake for total water, based on median intakes, is 4.0 litres (141 imp fl oz; 135 US fl oz) per day for males older than 18, and 3.0 litres (106 imp fl oz; 101 US fl oz) per day for females over 18; it assumes about 80% from drink and 20% from food.[2] The European Food Safety Authority recommends 2.0 litres (70 imp fl oz; 68 US fl oz) of total water per day for women and 2.5 litres (88 imp fl oz; 85 US fl oz) per day for men.[3]
The common advice to drink 8 glasses (1,900 mL or 64 US fl oz) of plain water per day is not scientific; thirst is a better guide for how much water to drink than is a specific, fixed amount.[4] Americans aged 21 and older, on average, drink 1,043 mL (36.7 imp fl oz; 35.3 US fl oz) of drinking water a day, and 95% drink less than 2,958 mL (104.1 imp fl oz; 100.0 US fl oz) per day.[5] Exercise and heat exposure cause loss of water and therefore may induce thirst and greater water intake.[6] Active people in hot climates may need 6.0 litres (211 imp fl oz; 203 US fl oz) of water, or more, per day.[6]
How much drinking water contributes to the intake of mineral nutrients is unclear. Inorganic minerals generally enter surface water and groundwater via stormwater runoff and through the ground. Water treatment also adds some minerals, such as calcium, zinc, manganese, phosphate, fluoride, and sodium compounds.[7] Water generated by the biochemical metabolism of nutrients provides a significant part of the daily water needs for some arthropods and desert animals, but provides only a small fraction of a human's necessary intake. There are trace elements in almost all potable water; some of these affect metabolism, such as sodium, potassium, and chloride, which are common in small amounts in most water. Other elements, such as fluoride, while beneficial in low concentrations, can cause dental and other problems at high levels.
Fluid balance is important to health. Profuse sweating can increase the need to replace electrolytes (salts). Water intoxication (the consumption of too much water too quickly) causes hyponatremia, which can cause death in minutes or hours.[8] Water makes up about 60% of the body weight in men and 55% of weight in women.[9] A baby is about 70% to 80%; old people are about 45% water.[10]
See also
editReferences
edit- ^ Ann C. Grandjean (August 2004). "3" (PDF). Water Requirements, Impinging Factors, & Recommended Intakes. World Health Organization. pp. 25–34. Archived (PDF) from the original on 22 February 2016. This 2004 article focuses on the USA context and uses data collected from the US military.
- ^ "US daily reference intake values". Iom.edu. Archived from the original on 6 October 2011. Retrieved 5 December 2011.
- ^ EFSA Panel on Dietetic Products, Nutrition, and Allergies (2010). "Scientific Opinion on Dietary Reference Values for water". EFSA Journal. 8 (3): 1459. doi:10.2903/j.efsa.2010.1459.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ H. Valtin, Drink at least eight glasses of water a day." Really? Is there scientific evidence for "8 × 8"? Archived 20 April 2010 at the Wayback Machine Am J Physiol Regul Integr Comp Physiol 283: R993-R1004, 2002.
- ^ Exposure Factors Handbook: 2011 Edition (PDF). National Center for Environmental Assessment. September 2011. Archived from the original (PDF) on 24 September 2015. Retrieved 24 May 2015.
- ^ a b "Report Sets Dietary Intake Levels for Water, Salt, and Potassium To Maintain Health and Reduce Chronic Disease Risk". US Institute of Medicine, Food and Nutrition Board. 11 February 2004. Retrieved 13 September 2017.
- ^ World Health Organization Archived 19 January 2011 at the Wayback Machine (WHO). Geneva, Switzerland. Joyce Morrissey Donohue, Charles O. Abernathy, Peter Lassovszky, George Hallberg. "The contribution of drinking-water to total dietary intakes of selected trace mineral nutrients in the United States." Draft, August 2004.
- ^ Noakes, Timothy D.; Goodwin, Neil; Rayner, Brian L.; Branken, Trevor; Taylor, Robert K.N. (2005). "Water Intoxication: A Possible Complication During Endurance Exercise☆". Wilderness & Environmental Medicine. 16 (4): 221–227. doi:10.1580/1080-6032(2005)16[221:WIAPCD]2.0.CO;2. PMID 16366205. S2CID 28370290.
- ^ Miller, Thomas A. (2006). Modern surgical care physiologic foundations and clinical applications (3rd ed.). New York: Informa Healthcare. p. 34. ISBN 978-1-4200-1658-1. Archived from the original on 1 September 2017.
- ^ Nancy caroline's emergency care in the streets (07 ed.). [S.l.]: Jones And Bartlett Learning. 2012. p. 340. ISBN 978-1-4496-4586-1. Archived from the original on 1 September 2017.