Editing Human nutrition (section)

=== Water ===
{{Main|Drinking water}}
[[File:TapWater-china.JPG|thumb|left|A manual [[water]] [[pump]] in [[China]]]]
Water is excreted from the body in multiple forms; including [[urine]] and [[Human feces|feces]], [[sweating]], and by [[water vapour]] in the exhaled breath. Therefore, it is necessary to adequately rehydrate to replace lost fluids.

Early recommendations for the quantity of water required for maintenance of good health suggested that six to eight glasses of water daily is the minimum to maintain proper [[Tissue hydration|hydration]].<ref>{{cite web | url=https://www.bbc.co.uk/health/healthy_living/nutrition/drinks_water.shtml | title=Healthy Water Living | publisher=BBC. Retrieved 1 February 2007 | archive-url=https://web.archive.org/web/20070101100025/http://www.bbc.co.uk/health/healthy_living/nutrition/drinks_water.shtml | archive-date=1 January 2007}}</ref> However, the notion that a person should consume eight glasses of water per day cannot be traced to a credible scientific source.<ref>{{cite journal | title="Drink at least eight glasses of water a day." Really? Is there scientific evidence for "8 × 8"? | journal=American Journal of Physiology. Regulatory, Integrative and Comparative Physiology | volume=283 | issue=5 | pages=R993–R1004 | doi=10.1152/ajpregu.00365.2002 | pmid=12376390 | year=2002 | last1=Valtin | first1=Heinz}}</ref> The original water intake recommendation in 1945 by the Food and Nutrition Board of the [[United States National Research Council|National Research Council]] read: "An ordinary standard for diverse persons is 1 milliliter for each calorie of food. Most of this quantity is contained in prepared foods."<ref>Food and Nutrition Board, National Academy of Sciences. Recommended Dietary Allowances, revised 1945. National Research Council, Reprint and Circular Series, No. 122, 1945 (Aug), pp. 3–18.</ref> More recent comparisons of well-known recommendations on fluid intake have revealed large discrepancies in the volumes of water we need to consume for good health.<ref name="Le Bellego">{{cite journal | vauthors=Le Bellego L, Jean C, Jiménez L, Magnani C, Tang W, Boutrolle I | title=Understanding fluid consumption patterns to improve healthy hydration | journal=Nutr Today | year=2010 | volume=45 | issue=6 | pages=S22–S26 | doi=10.1097/NT.0b013e3181fe4314 | s2cid=76128311 | doi-access=free}}</ref> Therefore, to help standardize guidelines, recommendations for water consumption are included in two recent [[European Food Safety Authority]] (EFSA) documents (2010): (i) Food-based dietary guidelines and (ii) Dietary reference values for water or adequate daily intakes (ADI).<ref name="Scientific Opinion on Dietary Reference Values for water">{{cite journal | author=EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) | doi=10.2903/j.efsa.2010.1459 | title=Scientific Opinion on Dietary Reference Values for Water | journal=EFSA Journal | year=2010 | volume=8 | issue=3 | page=1459 | s2cid=79245852 | url=http://orbit.dtu.dk/files/6350877/5.Scientific.pdf | archive-url=https://web.archive.org/web/20170922040703/http://orbit.dtu.dk/files/6350877/5.Scientific.pdf | archive-date=2017-09-22 | url-status=live}}{{open access}}</ref> These specifications were provided by calculating adequate intakes from measured intakes in populations of individuals with "desirable osmolarity values of urine and desirable water volumes per energy unit consumed".<ref name="Scientific Opinion on Dietary Reference Values for water" />

For healthful hydration, the current EFSA guidelines recommend total water intakes of 2.0 L/day for adult females and 2.5 L/day for adult males. These reference values include water from drinking water, other beverages, and from food. About 80% of our daily water requirement comes from the beverages we drink, with the remaining 20% coming from food.<ref>{{cite journal | last1=Armstrong | first1=Lawrence E. | last2=Pumerantz | first2=Amy C. | last3=Roti | first3=Melissa W. | last4=Judelson | first4=Daniel A. | last5=Watson | first5=Greig | last6=Dias | first6=Joao C. | last7=Sökmen | first7=Bülent | last8=Casa | first8=Douglas J. | last9=Maresh | first9=Carl M. | last10=Lieberman | first10=Harris | last11=Kellogg | first11=Mark | year=2005 | title=Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption | journal=International Journal of Sport Nutrition and Exercise Metabolism | publication-place=Champaign, Illinois | publisher=Human Kinetics Publishers | volume=15 | issue=3 | pages=252–265 | issn=1526-484X | pmid=16131696 | doi=10.1123/ijsnem.15.3.252 | url=https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=640f49f096f9a01e2c3ef103945a39830a12cd5c <!-- https://www.researchgate.net/profile/Mark-Kellogg/publication/7628664_Fluid_electrolyte_and_renal_indices_of_hydration_during_11_days_of_controlled_caffeine_consumption/links/09e4150bf9c40a8468000000/Fluid-electrolyte-and-renal-indices-of-hydration-during-11-days-of-controlled-caffeine-consumption.pdf -->}}</ref> Water content varies depending on the type of food consumed, with fruit and vegetables containing more than cereals, for example.<ref name="FAO">[http://www.fao.org/docrep/003/x9892e/x9892e00.htm "FAO Corporate Document Repository. Food Balance Sheets- A Handbook."] {{Webarchive|url=https://web.archive.org/web/20190217073049/http://www.fao.org/docrep/003/X9892E/X9892E00.HTM |date=2019-02-17 }} Retrieved 7 March 2011</ref> These values are estimated using country-specific food balance sheets published by the Food and Agriculture Organisation of the United Nations.<ref name="FAO" />

The EFSA panel also determined intakes for different populations. Recommended intake volumes in the elderly are the same as for adults as despite lower energy consumption, the water requirement of this group is increased due to a reduction in renal concentrating capacity.<ref name="Scientific Opinion on Dietary Reference Values for water" /> [[Pregnant]] and [[breastfeeding]] women require additional fluids to stay hydrated. The EFSA panel proposes that pregnant women should consume the same volume of water as non-pregnant women, plus an increase in proportion to the higher energy requirement, equal to 300 mL/day.<ref name="Scientific Opinion on Dietary Reference Values for water" /> To compensate for additional fluid output, breastfeeding women require an additional 700 mL/day above the recommended intake values for non-lactating women. Dehydration and over-hydration&nbsp;– too little and too much water, respectively&nbsp;– can have harmful consequences. Drinking too much water is one of the possible causes of [[hyponatremia]], i.e., low serum sodium.<ref name="Scientific Opinion on Dietary Reference Values for water" /><ref>{{cite journal | pmc=1770067 | title=Fatal water intoxication | journal=Journal of Clinical Pathology | date=October 2003 | pmid=14514793 | volume=56 | issue=10 | vauthors=Farrell DJ, Bower L | pages=803–04 | doi=10.1136/jcp.56.10.803-a}}</ref>