Health and Hydration

By Susan Greeley, MS, RDN

During the heat of summer with peak humidity, it’s hard not to think of hydrating! Yet, drinking enough water and staying properly hydrated is essential to health at all times. Simply put, water sustains life!

Water in our bodies

Adults are roughly 60% water, which is why we can’t go without it for more than a short time before negatively impacting our functioning and health. Water is in each cell, is the main component of blood, and makes up our muscles and organs as well. That said, it maintains blood volume and allows muscle contractions to occur. Water also serves to transports nutrients, remove waste products through adequate urine and protects our vital organs.

Water and proper hydration also help us to regulate our body temperature. This function alone is often altered in aging adults, who sometimes lose the sensation for thirst, consume inadequate fluids and frequently suffer from dehydration. When we sweat, we also lose water, and it is easy to become dehydrated in hot climates even without exercise.

Being active increases your water needs even more, mostly due to the loss through sweat. If you don't replenish the water loss, you can become dehydrated.

Dehydration negatively affects mental and physical performance and can lead to impaired coordination, inability to make appropriate decisions, an increase in body temperature, and strain on the cardiovascular system. Signs of dehydration include thirst, dizziness, headache, muscle cramps, and dark urine, as well as increased/excessive hunger between meals.

With all of the critical roles that water plays in our bodies, it’s clear we need a constant supply of water. But the numbers we’ve all heard about how much water to consume are often conflicting and can be overwhelming for individuals who don’t like to drink water.

How much water do we need daily?

Generally speaking, adult women need about 2.7 liters of water per day and adult men require an amount closer to 3.5 liters. These are, however, mere guidelines, as there is great individual variability based on age, weight, stature, exercise and environmental factors.

A guideline that may be easier to remember is to consume half of your body weight in ounces. (If you weigh 160 pounds, you need about 80 ounces of water.) With exercise and hot, dry climates, your water needs increase.

If the task of consuming that fluid seems daunting -- particularly for those of you who don’t drink enough water, for taste or other reasons -- then rest assured that there are more enjoyable ways to reach your daily water consumption goals. The good news is that our diet usually provides more than half of what we need. It turns out that we actually consume about 50% of our daily water through our diet, so it can be easier to get enough water than many people realize!

Sources of water

Since water is an essential nutrient, there are several ways that help ensure humans actually get it:

• Drinking water (the obvious source) and other liquids
• Eating foods, particularly high water content fruits and vegetables
• Producing water in our cells – a byproduct of cellular metabolism (breaking down carbohydrates, fats and proteins)

To reiterate, the foods and beverages we eat provide about 50% or more of our daily fluid, and that number, of course, increases the more “high water content” foods -- and “other” beverages – that we consume. What’s more, you can see and feel the benefits of good hydration, as skin is more “supple” and  weight is truly easier to manage when you eat and drink water! It’s intuitive that the more water a food contains, the less energy-dense it is, meaning the fewer calories it has.

Here’s a list of my recommended daily foods to consume for ensuring adequate water intake while not overdoing calories:

Fruits and vegetables that are at least 90% water:

Melons
Grapefruit
Strawberries
Lettuces
Celery
Fennel
Cucumber
Cabbage
Bell peppers
Broccoli
Cauliflower
Spinach
Zucchini
Tomatoes
Radishes
Mushrooms
Eggplant

Other foods and fluids that are high in water or mostly water:

• All fruits and vegetables
• Soups and broth,
• Juices and smoothies
• Coffee and tea
• All-fruit (100% fruit) sorbets

How to hydrate: Tips for hydration and exercise

As a word of caution, it is possible to drink too much water. While not common, over-hydration is most often seen in recreational athletes. Consuming excessive fluids has the potential to cause a serious condition called hyponatremia, or low blood sodium. Signs of this include swelling of hands and feet, weight gain during exercise, confusion and vomiting.

To ensure you optimize your fluid intake, here is a summary of tips to help:

• Drink about half your body weight in ounces daily (includes coffee, teas, juices. Increase as necessary with exercise.)
• Sip on fluids throughout the day and during exercise. It’s important not to “chug” water or other fluids. Drink at a rate that's comfortable without chugging.
• Water is the most effective drink when doing low intensity or short duration sports.
• Always begin exercise well-hydrated.
• When doing high intensity training or endurance activities for more than 60 minutes, sports drinks can be used to provide a source of carbohydrates and electrolytes.
• Weighing yourself before and after a workout can help you know how to drink and replenish losses.
• If there was no weight change, drink according to your thirst and overall goal fluid intake for the remainder of the day.
• If weight loss was experienced, drink 16 to 24 ounces of fluid per 1 lb of weight you lost, and again, don’t chug!

Bottom line: Hydration and health go hand-in-hand, and it’s easier to “get enough water” than most people realize. Simple additions to your diet with things like lettuce on a sandwich only adds to your water and not your calorie intake. Soup and salad are also a perfect hydration meal! I encourage everyone to eat high water content fruits and vegetables daily, and while water is still the best drink for all humans, you can enjoy a wide variety of foods and fluids daily while ensuring you stay properly hydrated. From your skin to your muscles, you’ll look and feel better when you’re hydrated!