Water, Hydration and Health

Barry M. Popkin et. al., Water, Hydration and Health, Nutr Rev. 2010 Aug; 68(8): 439–458.

ABSTRACT
This review attempts to provide some sense of our current knowledge of water including overall patterns of intake and some factors linked with intake, the complex mechanisms behind water homeostasis, the effects of variation in water intake on health and energy intake, weight, and human performance and functioning. Water represents a critical nutrient whose absence will be lethal within days. Water’s importance for prevention of nutrition-related noncommunicable diseases has emerged more recently because of the shift toward large proportions of fluids coming from caloric beverages. Nevertheless, there are major gaps in knowledge related to measurement of total fluid intake, hydration status at the population level, and few longer-term systematic interventions and no published random-controlled longer-term trials. We suggest some ways to examine water requirements as a means to encouraging more dialogue on this important topic.
Keywords: water, hydration, water intake, water measurement, recommended daily intake, water adequacy

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/