Metabolic water
Metabolic water refers to water created inside a living organism through their metabolism, by oxidizing energy-containing substances in their food. Animal metabolism produces about 100 grams of water per 100 grams of fat,[1] 42 grams of water per 100 g of protein and 60 grams of water per 100 g of carbohydrate.[1][2][3]
Some organisms, especially xerocoles, animals living in the desert, rely exclusively on metabolic water. Migratory birds must rely exclusively on metabolic water production while making non-stop flights.[4][5] Humans, by contrast, obtain only about 8-10% of their water needs through metabolic water production.[6]
In mammals, the water produced from metabolism of protein roughly equals the amount needed to excrete the urea which is a byproduct of the metabolism of protein.[6] Birds, however, excrete uric acid and can have a net gain of water from the metabolism of protein.
References
- ^ a b http://www.nature.com/nature/journal/v150/n3792/abs/150021a0.html
- ^ http://www.encyclopedia.com/doc/1O39-metabolicwater.html
- ^ 4 Water | Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate | The National Academies Press. p. 85. doi:10.17226/10925.
- ^ http://dissertations.ub.rug.nl/faculties/science/2005/s.b.engel/
- ^ Klaassen M (1996). "Metabolic constraints on long-distance migration in birds". J Exp Biol. 199 (Pt 1): 57–64. PMID 9317335.
- ^ a b Board on Agriculture and Natural Resources (BANR), Nutrient Requirements of Nonhuman Primates: Second Revised Edition (2003), p. 144. [1]