Did you know that you can live a lot longer without food than without water? “Simply put, without water, there is no human life as we know it,” says Donald Kirby, MD, director of the Center for Human Nutrition at the Cleveland Clinic. Our bodies use water for a myriad of essential functions. On the cellular level, water carries nutrients and oxygen to cells and helps the body absorb minerals and other nutrients. It’s responsible for supporting many bodily systems, including metabolism,
protecting body organs and tissues, and providing a moist environment for mouth, eye, ear, nose and throat tissues. On a large scale, it regulates body temperature. Staying in tune with your body’s need for water can also help with weight loss. Oftentimes it’s easy to mistake thirst for hunger. Drinking more water may curb your appetite and help you reach your diet goals.
Getting the H20 You Need
While there is no hard and fast rule for the amount of water an individual should drink in a day, you can still figure out how much your body may require. You may have heard the commonly used 8 x 8 rule (drinking eight 8-ounce glasses a day). It’s a fair place to start, but this rule doesn’t account for individual needs, which vary based on body weight, activity level and environment. To determine how much water your body needs, take your weight and divide it by two. This will give you the daily value of water in ounces. For example, a person weighing 150 pounds needs to drink 75 ounces a day.
Certain conditions require you to increase your water consumption, including exercise, climate and physical condition:
Before, during and after physical exercise. Basically, the more you sweat, the more water you need to replace. But don’t rely on feelings of thirst to get you guzzling. By the time you’re thirsty, you’re already dehydrated! Follow the American Council of Sports Medicine’s recommendation for hydrating when you exercise:
1–2 hours before: Drink 12–16 ounces of water.
10–15 minutes before: Drink 12–16 ounces of water.
During: Drink 3–4 ounces every 15 minutes.
After: For 30 minutes after exercise, drink 12–16 ounces for every pound lost through sweat during exercise. To calculate, weigh yourself before and after your workout.
No need to hydrate with electrolyte-enhanced, high-calorie sports drinks unless you exercise for more than an hour. If your workout is less than an hour, water is all you need.
- In hot climates and high altitudes. High temperatures and altitudes cause water to evaporate off of the body faster. In high heat, water helps cool the body through sweat. The more sweat you produce, the more water and energy your body burns, and the more you need to replace. If temperatures are extremely high, sweating is not enough to regulate body temperature and exercise can be dangerous. In these cases, drink more water (as much as 96 ounces), stay in a cool area, and avoid strenuous activity.
- For illnesses or health conditions. For individuals with medical conditions, such as congestive heart failure, kidney disease or failure, or cirrhosis of the liver, excess fluid intake can often exacerbate the underlying disease, says Dr. Kirby. It’s important to work with your physician and perhaps a registered dietitian to find the optimal fluid intake for you. You can tell when there is an imbalance of fluid in your body when you can press a finger on your feet, ankles or legs and make an impression. This is called “pitting edema” and represents a total body excess of salt and water. If you notice this, bring it to your doctor’s attention immediately.
- During pregnancy or breast-feeding. An undernourished and fluid-deprived mother can’t make sufficient milk to adequately nourish and hydrate an infant. When you’re pregnant, your body needs three liters (101 ounces) of water a day. When you’re breast-feeding, try to get 3.8 liters (128 ounces) a day.
Food Helps Hydrate Too
Drinking water isn’t the only way to stay hydrated. Specific foods account for about 20 percent of your total water intake in a day. If you’re trying to increase your water consumption, look to fruits like watermelon to help get the amount you need. Vegetables like tomatoes, lettuce, cucumbers, zucchini and radishes all contain over 95 percent water. You can drink beverages like coffee and tea to help with water intake, but water is always your best bet. If you prefer flavored beverages, try water with a slice of cucumber, lemon, orange, or a sprig of mint for a fresh taste.
The Dangers of Dehydration
Knowing the signs of too little water can save you from serious illness. Mild dehydration starts with a feeling of thirst. Other signs mean dehydration is intensifying. Watch out for: dark yellow urine, headache, dizziness and lightheadedness, especially with a change in position such as going from sitting to standing. As dehydration progresses, you may notice that you can’t think well and that you feel tired. You may even notice a decline in hand-eye coordination and control of other parts of your body. You may detect muscle weakness and memory loss. If it seems that dehydration may be causing these symptoms, then you should begin increasing your fluid intake. And just as important, try to determine what factors caused this event so you can address the problem.
Hopefully you’ll never experience what’s known as severe dehydration. It, too, starts with a feeling of thirst, but one that’s extreme. Urine may turn amber or brown, or you may have little to no urine at all. You may get dry, cracked lips, dry mouth, dry skin that looks parched and sunken eyes. You’ll notice that your body stops sweating (there’s no water!). Irritability and confusion, low blood pressure, feelings of heart racing or rapid beats are other symptoms. You can have a fever, and in serious cases of dehydration, you may be delirious or lose consciousness. These would be the signs and symptoms of a medical emergency, and you should seek immediate medical care. This type of dehydration is more common in severe conditions — for example, in extreme heat with physical exertion or with medical illnesses such as excessive vomiting and diarrhea.