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.
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:
Signs of dehydration:
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.
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.
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.
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:
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.
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.
INGREDIENTS:
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