August 2025 Corporate Newsletter: Hydration Myths Debunked

HYDRATION MYTHS DEBUNKED

Contributed by Heidi Roth, RDN, CHHC

As the summer heat continues, many of us are doing our best to stay cool and hydrated – and with good reason! The human body is composed of 50-75% water (depending on sex and age), with about two-thirds of that water housed inside our cells. Hydration plays a vital role in how we feel and function, influencing everything from energy levels and metabolic health to digestion. Even mild dehydration can make us feel sluggish and lethargic.

Even though water is essential for life, there still seems to be some confusion about what optimal hydration looks like. Let’s clear up a few common myths.

Myth #1: You have to drink eight 8-ounce glasses of water a day.

Fact: Surprisingly, this long-standing guideline is not based on science. Hydration needs vary
widely from person to person, based on climate, age, sex, health status, and activity level!

In general, women need roughly 9-10 cups/day and men need about 13-15 cups of water/day from ALL food and fluid sources. Another helpful rule: Divide your weight in half – that’s roughly the number of ounces of water you need per day.

3 ways to tell if you are well hydrated:

1. Urine colorAim for pale straw-colored urine. Dark yellow or amber urine = dehydration. Keep in mind some medications and vitamins may affect urine color.
2. ThirstGenerally, thirst is an excellent marker of hydration status ( except in the elderly – this mechanism is not as reliable the older you get).
3. Weight A marked decrease in weight from one day to the next can indicate dehydration – a pound is equal to 16 oz of fluid.

Signs of dehydration:

• Thirst
• Dry mouth and lips
• Headache
• Fatigue
• Dizziness

Myth #2: Only plain water counts for hydration.

Fact: Not true! Many foods and beverages count towards your daily fluid needs. Fruits and vegetables, soups, stews, yogurt, milk, and smoothies all contain water – and as an added bonus they contain a lot of the electrolytes that help maintain fluid balance. Some notably hydrating fruits and vegetables include melon, cucumbers, red peppers, zucchini, and celery. And don’t forget unsweetened herbal teas – they’re not only hydrating, but also rich in antioxidants.

Myth #3: Caffeinated drinks like coffee and tea dehydrate you.

Fact: Good news! Moderate amounts of coffee and tea count towards your fluid intake! While caffeine has a very mild diuretic effect, it doesn’t offset hydration for most people. That said, you may want to limit caffeinated beverages in the afternoon to support better sleep at night.

Myth #4: Sparkling water and seltzer don't count.

Fact: Both sparkling water and seltzer are just as hydrating as still water. However, there are some additional things to consider. Carbonated water contains carbon dioxide which interacts with saliva to form carbonic acid – a weak acid that has the potential to be erosive to your teeth, as well as contribute to cavities. Still, they’re much less damaging to teeth than sugary sodas or fruit juice, so consuming 1-2 cans per day should not be too much of a concern.

Myth #5: The more water you drink, the better!

Fact: While most people are worried about drinking enough, it is possible to drink too much water. Although it’s very rare, over-hydration, also known as water intoxication, can lead to dangerously low blood sodium levels.

Signs of over-hydration include:

• Constantly drinking water
• Completely clear urine
• Swelling and rapid weight gain
• Confusion, dizziness, and nausea
• In severe cases: coma and seizure

If you are always thirsty no matter how much you drink, please check with your healthcare practitioner as this can be a sign of pre-diabetes or diabetes.

Myth #6: You need to add electrolytes to your water.

Fact: While it’s true that oral rehydration solutions containing small amounts of electrolytes and sugar can be helpful in certain situations – like during intense exercise or when rapid rehydration is needed, for most people, plain water is perfectly adequate for drinking during the day.

If you are exercising for more than an hour or sweating heavily you may want to consider a sports drink to replace what’s lost. Fluids that contain a bit of salt and natural sugar can also be very hydrating, such as the recipe for agua fresca below.

RECIPE CORNER: Melon Agua Fresca

INGREDIENTS:

• 4 cups cubed, seeded melon such as watermelon or honeydew – strawberries and cucumber are also delicious!
• 3 cups cold water
• 1-2 TB lime juice
• 1 TB sweetener such as honey or agave, to taste
• Salt (optional)
• Chia seeds, mint leaves (optional)
  
  PREPARATION:

1. Combine chopped fruit, 1/2 cup of the water, lime juice, 1/8 tsp salt and sweetener in a blender until smooth.
2. Strain the mixture into a pitcher through a fine-mesh sieve (this is optional and will result in a smoother drink.) Stir in the rest of the water.
3. Chill. When ready to serve, pour over ice in glass, optionally adding to each glass 1 tsp chia seeds and a couple of mint leaves.

How are you keeping hydrated this summer?

Heidi Roth RDN, LDN, is a Registered/Licensed Dietitian, Health Coach and nutrition expert with a passion for health and wellness. She graduated from the University of Pittsburgh with a BS in Nutrition and Dietetics.

August 2025 Corporate Newsletter: Hydration Myths Debunked