Most men can get the water they need from their usual diet and by drinking when they are thirsty.
Especially in hot weather, we are urged to drink adequate fluids and be on guard for dehydration. That may be why you see people toting bottled water everywhere, propelled by the myth that you need to drink eight glasses of water a day to be healthy.
Drinking eight 8-ounce (1 cup) glasses of water—about a half-gallon of fluid—is no small feat. But you may not need to drink that much water every day to prevent dehydration.
“In the summer, when it’s very hot and you are sweating more and exercising a lot, yes, you need to drink more fluids, but the average person doesn’t necessarily have to drink eight glasses of water a day,” says Dr. Melanie Hoenig, an assistant professor of medicine at Harvard-affiliated Beth Israel Deaconess Medical Center.
Meeting daily needs
An individual’s daily water needs vary substantially, based on body size, physical activity level, the local climate, and other factors.
However, to provide general guidance, the Institute of Medicine (IOM) suggested an “adequate intake” of water for men of 3.7 liters a day (about 16 cups) from all sources, including food, beverages, and drinking water.
Food and beverages at meals fulfill most of our daily need for fluids. A breakfast of 1 cup shredded wheat
cereal w. milk, cut fruit, toast, orange juice, and coffee provides about 28 ounces of water.
But this figure can be misleading. The adequate intake recommendation is based on a national dietary survey of the total water from foods and beverages that most reportedly healthy men take in every day. “It is based on surveys of what people do, not on what they need,” Dr. Hoenig says. For a substantial percentage of men—particularly those over 65—the IOM’s recommended adequate intake of 16 cups could be excessive.
So how do you make sure you get enough fluids? Your diet—food plus all beverages—supplies at least 70% of daily needs, according to the national dietary survey data. The beverages include milk, soft drinks, tea, and coffee. As for the rest of your daily fluids, just wait for the body to send you a message that you need to reach for a glass of water. It’s called “thirst.”
Best source of fluids?
You can’t go wrong by drinking plain water, though all beverages containing water contribute toward your daily needs. And it’s a myth that caffeinated beverages or those containing alcohol are dehydrating because they make you urinate. They do, but over the course of the day, the water from these beverages still leads to a net positive contribution to total fluid consumption.
In addition, you can meet your fluid needs without special sports drinks. These contain water, sugar, flavorings, and minerals such as sodium and potassium. Manufacturers try hard to convince active men that sports drinks prevent dehydration, but even for athletes, the evidence for this is controversial. An otherwise healthy man who chugs sports drinks instead of water could be just adding empty calories without getting any clear health benefit.
Certain men may need to be more mindful of fluid consumption. For example, make sure you drink plenty of water when taking large daily doses of nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen (Advil, Motrin) and naproxen (Aleve). “If you were very behind in your fluids and you took NSAIDs, that could cause kidney problems,” Dr. Hoenig says.
Men with a propensity to kidney stones can help to prevent them by drinking a large amount of extra water. Research suggests drinking two quarts of water a day helps reduce the incidence of kidney stones.
Too much water can also be a problem in some cases. For example, men with heart failure need to watch how much they drink to prevent fluid build-up in their lungs. Men with reduced kidney function could also get overloaded if they drink too much water.
If you think you may have to limit your water, ask for advice from your doctor. “Drinking too much water can have bad effects, too, so that’s why water intake needs to be tailored to the individual,” Dr. Hoenig says.