How much water you might actually need, signs of dehydration, and more helpful tips on staying hydrated

It's summer and the heat is on! 

It's been so hot that students have been having a hard time concentrating on their lessons, a huge majority of teachers have reported.

Meanwhile, the Metro Manila Development Authority is giving their personnel 30-minute breaks during summer months to protect from heat stroke, heat exhaustion, and heat cramps.

The Department of Health (DOH) recently cautioned the public against heat exhaustion and reminded people to stay hydrated.

According to Joemarc Dela Cruz, a nutrition-dietitian at Lifescience Center in Bonifacio Global City, water is the beverage of choice that keeps people well-hydrated, especially if they are already relatively healthy.

How much water do we need?

He said this is because water "requires the least processing by the body to be absorbed."

But while eight glasses of water a day is the common knowledge, the independent USA-based Beverage Guidance Panel of six experts, including Dr. Walter C. Willett of the Harvard School of Public Health’s Department of Nutrition, said there’s little evidence to support the much-touted advice that people need eight glasses of water a day. 

According to the Harvard T.H. Chan School of Public Health, experts recommend the average woman should drink approximately 11 cups of water per day, while the average man should have 16 glasses.

The American-based National Academy of Science, formerly known as the Institute of Medicine, puts the number at about 15 cups for men and echoes the 11 cups for women.

The National Academy of Medicine reported the same thing: women should get 2.7 liters, which is equivalent to about 11 glasses of water per day.

Still, there are various factors that determine how many glasses of water you'll need.

For instance, people who exercise regularly will need more water than those who don't. Women who are breastfeeding also need more water than those who aren't.

For a good basis to determine how many glasses of water you need, Joemarc shared a formula: Divide by two your weight in pounds and then multiply that by 30 to get your water requirements in milliliters. Divide that by 240 and round up the figure to the nearest whole number and that's your water requirement in number of glasses. 

So if you're a 120lb woman, you'll need 7.5 glasses of water. 

Why is hydration important?

According to the Cleveland Clinic, being properly hydrated helps with your mental and physical performance, energy level, skin health, gastrointestinal function, and the balance of important minerals in the body.

It also helps address headache frequency and intensity, and it's good for your organs, like your heart, kidneys, and brain.

While water is still best, Joemarc said, "any potable or safe drinking beverage can contribute to one’s total hydration."

He cautioned against caffeinated beverages, specifically coffee and tea, for people with pre-hypertension and hypertension, which is elevated blood pressure because "caffeine constricts blood vessels and further increases blood pressure."

Besides, "caffeine also is a diuretic, stimulating individuals to urinate more. This is counterproductive of achieving optimal hydration status through drinking fluids," he added.

And if you're thinking what we're thinking, sorry that's a no. Beer, wine, and hard liquor aren't recommended for hydration because like caffeine, these alcoholic beverages are diuretics that increase water loss through urination.

In case you were wondering, sports beverages are usually reserved for individuals who are physically active, athletes, and anyone who joins sports competitions, Joemarc said.

The only people who really need them are athletes who exercise for more than an hour at a time and sweat a lot, according to the American Journal of Clinical Nutrition.

The journal added that sports drinks aren’t needed by casual athletes or daily walkers and the like.

According to Joemarc, sports drinks contain fluids with sugar and electrolytes that help replenish the body at a faster rate during intense physical activities or competitions.

Signs of dehydration to watch out for

According to Joemarc, mild dehydration results in loss of cognitive function, loss of alertness, increased heart rate, and decreased exercise performance.

Moderate dehydration meanwhile leads to damaged organ systems, and severe dehydration may lead to death.

"Contrary to popular belief, thirst is not an effective signal to consume fluids especially for individuals at risk for dehydration," said Joemarc.

Instead, be on the look out for common symptoms of dehydration which includes headache, fatigue, decreased appetite, lightheadedness, poor skin elasticity, sunken eyes, dry mouth and nose, and blood pressure changes.

Concentrated urine — or pee that is dark yellow and with a strong odor — and decreased urine output — fewer than four days a day — are also symptoms of dehydration.

Over-the-counter oral rehydration salts (ORS), which contains electrolytes and carbohydrates dissolved in liquid, can help combat mild dehydration, Joemarc said.

"It can be used as a first aid approach for mild dehydration, in addition to increasing oral intake of plain water," said Joemarc.

If symptoms don't improve or are reoccurring, then you'll need to consult your primary care physician.

Additional tips to stay hydrated

According to UCLA Health, you may usually get about 20% of the water you need in a day from the food you eat.

To help boost that, you can try packing your meals with water-rich food. Cucumber and iceberg lettuce have the most water content at 96%.

Rounding out the top 15 water-rich food are celery, radish, romaine lettuce, tomato, zucchini and summer squash, asparagus, bell pepper, cabbage, cauliflower, mushroom, spinach, strawberries, and watermelon.

If you get sick and can't keep food or beverages down, Joemarc suggests broths or clear soup made from meat, poultry, fish, or vegetables.

Once you know how many glasses of water you need to stay hydrated, Joemarc also suggested to set phone reminders, alarms, or sticky notes to remind you to drink if you keep forgetting or get too busy to drink liquids throughout the day.

He also suggested keeping a tumbler next to you to not only remind you to drink liquids, but allows you to monitor how often you've already refilled it.

For the summer heat, he recommends "chilled beverages."

Mount Sinai also advised that you can sip on ice cubes for some hydration. Just be sure that the water used to make the ice cubes was also filtered.

Joemarc said that you can complement these by wearing proper attire and staying away from direct sunlight.

Stay well-hydrated, mga Kapuso! — LA, GMA Integrated News