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Summer Heat Waves Can Cause Risk for Dehydration
Provided by the American Dietetic Association: Your Link to Nutrition & Health

Whether you are lounging poolside, playing tennis or simply watching T.V. at home, it is essential to consume plenty of fluids during summer heat waves.

On average, an adult's body weight is made up of about 10 to 12 gallons of water (about 55 to 75 percent of body weight). An elderly person's body weight is only about half water. But, when exposed to extremely high temperatures, your body requires even more water to maintain its normal temperature.

Extreme weakness and potential heatstroke may result if more than 10 percent of body weight is lost from dehydration or water loss. And the average adult loses about 2 1/2 quarts (about 10 cups) of water daily through perspiration, breathing and other body functions.

What are the signs of dehydration?

The effects of the body's loss of water are progressive: thirst, then fatigue, next weakness, followed by delirium and, finally, death. Though dehydration typically won't happen over the course of a single day, it is important to pay attention to signals of water loss and minimize risk of dehydration by drinking plenty of fluids throughout the day--before thirst sets in.

What's to drink and how much?

Of course, the most important fluid to consume is plain water, at least 8 to 12 + 8 ounce cups per day. If you are physically active, you should add one to three cups for each hour of activity. If your prefer a flavored beverage, milk and fruit juice are good options that provide other nutrients or try sports drinks or decaffeinated beverages (caffeine can act as a diuretic, causing water loss). Alcoholic beverages have a diuretic effect and promote water loss, so try alternating them with water or sparkling water at parties and social gatherings.

Food, a water source?

While water and other beverages supply the body with a good portion of its fluid needs, solid food also provides a surprising amount. Consider preparing your meals with these foods during the summer heat waves:

Food Serving % Water by Weight
Lettuce 1/2 cup
Watermelon 1/2 cup
Broccoli 1/2 cup
Grapefruit 1/2 cup
Milk 1 cup
Orange juice 3/4 cup
Carrot 1/2 cup
Apple 1 medium
Cottage cheese, low-fat 1/2 cup
Fruit & Juice bars 3 ounce bar
Yogurt 1 cup
Potato, baked with skin 1 medium
Tuna, canned & drained 3 ounces
Rice, cooked 1/2 cup
Pasta, cooked 1/2 cup
Chicken, roasted, no skin 3 ounces
Vanilla frozen yogurt, soft serve 1/2 cup

Table Source: Calculated from Bowes & Church's Food Values of Portions Commonly Used, 16th Edition, Jean A. T. Pennington, Philadelphia: J.B. Lippincott Company, 1994.

Final word

Overall, cool refreshing drinks can help lower your body's temperature. But remember, it's harder to cool down in hot, humid weather because perspiration doesn't evaporate as quickly as it does in hot, dry weather.

* Information provided from The American Dietetic Association's Complete Food & Nutrition Guide.


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