Your body cannot survive without adequate water intake because the fluid supports every cell in your body. Just a 1 to 2 percent drop in hydration levels can lead to dehydration symptoms such as impaired exercise performance, fatigue and thirst. Water is essential, but it's not magical. Many myths attribute weight loss, skin health and toxin elimination to water consumption. How much water you need to consume daily and from which sources are also up for debate.
You Need Eight Glasses a Day
You may have heard that you need eight glasses of water per day for optimal health. The origins of this recommendation, though, are unknown. A paper in a 2002 issue of the "American Journal of Physiology" found that, despite not consuming this amount of water, thousands of adults are healthy and not ill. If you live in a hot climate, are particularly active or have certain medical conditions, though, a higher intake of water may be warranted. Not everyone needs eight glasses per day, especially the average, sedentary person, notes Dartmouth Medical School physician Heinz Valtin, author of the paper.
Bottled Water Is Best
The "Washington Post" reports that America's tap water is among the safest in the world. City tap water is tested every few hours, while the sources for bottled water are tested just once per week. Bottled water comes at a premium and is usually sold in plastic bottles that leach toxins, especially when left out in the heat of the day. If you are concerned about the quality of your tap water, install a filter or use a pitcher that filters water for you. Carry water in stainless steel bottles when you're on the go.
Water Helps You Lose Weight
Many weight-loss gurus suggest drinking water before a meal to squelch your hunger. Evidence that this practice actually decreases your calorie intake is scant, though, reports a 2008 paper published in the "Journal of the American Society of Nephrology." In some cases, you may mistake thirst for hunger -- so it isn't a bad idea to have a glass if you're craving food but it hasn't been long since your last meal. Drinking water may increase your metabolic rate -- but whether it's enough to induce significant weight loss is unclear. A study published in the "Journal of Clinical Endocrinology and Metabolism" in 2007 found that just 16 ounces of water increased metabolism by 24 percent for one hour. Over the course of a day, this could add up to about 95 extra calories burned -- if you drink about 75 ounces, or two liters, every day. Although the boost in calorie burn is nice, it's probably not enough to curb obesity.
Water Cleanses You of Toxins
You may urinate more when you drink lots of water, but this isn't an indication that your kidneys are working more effectively in clearing toxins from the body. Increased water intake hasn't been shown to improve the functioning of other organs, either, according to the paper in the "Journal of the American Society of Nephrology." This includes the largest organ in your body -- the skin. If you are clearly dehydrated, your skin will suffer -- but no research supports the assertion that overhydrating will improve skin tone or health. If you find that drinking more water makes you feel good, though, and that the extra trips to the restroom aren't a hassle -- extra water doesn't seem to do your body any harm.
- Journal of the American Society of Nephrology: Just Add Water
- ND Health Facts: Dehydration
- American Journal of Physiology: "Drink at Least Eight Glasses of Water a Day.” Really? Is There Scientific Evidence for “8 × 8”?
- Washington Post: Five Myths About Water
- Chris Kresser: The Water Myth
- Journal of Clinical Endocrinology and Metabolism: Water Drinking Induces Thermogenesis Through Osmosensitive Mechanisms
- Journal of Clinical Endocrinology and Metabolism: Water-Induced Thermogenesis