We often hear that we should drink eight 8-ounce glasses of water a day. However, there is some controversy about this figure and what it really means.
Water is an essential nutrient. It is necessary to sustain all forms of life, and humans can only live a few days without it. It is also a healthful drink.
Health authorities and others often encourage people to consume 2 or more liters of water a day, but is this only plain water or does water from other sources count?
How much plain water do we really need?
Fast facts on water intake
Here are some key points about daily water consumption. More detail and supporting information is in the article.
Foods and fluids, including water, are the main source of water in our bodies.
The advice to drink eight 8-ounce glasses of water a day is not based on evidence.
The amount of water we need depends on individual needs and circumstances, including activity and climate.
The healthy body naturally maintains a well-tuned balance of fluid, and the thirst mechanism tells us when we need more.
In 1945, the U.S. Food and Nutrition Board advised people to consume 2.5 liters (84.5 fluid ounces (fl oz) of water a day, including fluid from prepared foods.
Today, the Centers for Disease Control and Prevention (CDC) say, "There is no recommendation for how much plain water adults and youth should drink daily." However, there are recommendations about total fluid intake from all sources.
Older adults may be at risk of both dehydration and overhydration, as a result of health conditions, medications, loss of muscle mass, reduction in kidney function, and other factors.
Older adults who are well hydrated have been found to have:
fewer falls
less constipation
in men, a lower risk of bladder cancer
Dehydration has been linked to a higher frequency of:
urinary tract infections
confusion
kidney failure
slower wound healing
Few studies have looked at fluid input and output in older people, but at least one has concluded that it is not significantly different from that of younger people.
Those caring for older people are encouraged to provide fluids regularly and assist with ambulation, especially if a reduction in mobility makes it harder to visit the bathroom.
Sources of water
Water in the body comes not only from drinking water.
Estimations vary, but according to one source: around 20 to 30 percent comes from food, some 60 to 70 percent comes from drinking water and other fluids and a small percentage, about 10 percent is "metabolic water," produced by cells during normal cell function
*The more active the body is, the more metabolic water is produced.
Some surveys suggest that around 20 percent of water intake comes from foodstuffs and the rest is from fluids. This depends on diet. A higher intake of fresh fruit and vegetables will mean a higher intake of water from foods.
The CDC urge people to make sure they drink enough water before, during, and after physical work, especially if this involves activity in a hot climate. This can help maintain alertness and effectiveness.
In a hot environment, you may need one 8-ounce cup every 15-20 minutes, but not more than 48 ounces in one hour, as this can lead to hyponatremia, a low level of sodium.
Plain water provides hydration without adding calories or jeopardizing dental health. Sports drinks can be useful in moderation, but too many will add unnecessary sugar to the body.
There is sooo much more information about water in this article. To read more about types of water such as tap vs.bottled, coffee intake, exercise, calculating water needs. Please check out the full article
https://www.medicalnewstoday.com/articles/306638.php#-calculating-human-water-needs-