I’ve saved the MOST important nutrient for last. Although we can live for weeks without food, we cannot survive for more than a few days without water. Water is considered an essential nutrient. An essential nutrient is a nutrient that is required for normal physiological function that cannot be made by the body—it has to be provided through the diet. The six essential nutrients include carbohydrates, protein, fat, vitamins, minerals and water.
Body water has many functions in the body:
- Moistens tissues (mouth, eyes, and nose)
- Protects body organs and tissues
- Helps with digestion
- Helps to dissolve minerals and other nutrients to make them available to the body
- Regulates body temperature
- Lubricates joints
- Helps body to get rid of waste products
- Carries nutrients and oxygen to cells
How Much is Enough?
The amount of water you need depends on a variety of factors, including your age, body size, the climate you live in, how physically active you are, how much you sweat, medications you may take, and whether you’re experiencing an illness or have any other health issues.
On average your body weight is approximately 60 percent water. Leaner people have more body water (because of greater muscle mass), and people with more body fat have less body water.
While most of us can recite everything we had to eat for the day—we’re not sure how much fluid we’ve consumed. Do you know how much water you have each day? Furthermore, do you know how much your body needs? For most of us, our fluid intake falls short of our daily requirements.
Know Your Numbers
Here’s an easy way to calculate your daily fluid goal. The rule of thumb is that you need 1 milliliter (ml) of water for every 1 calorie intake. For example, if your calorie needs are 2500 calories/day, your water intake should be approximately 2500 ml (about 2.5 liters). That translates into ~10 cups of water each day. Another approach is to divide your weight in half to get the total number of ounces that you need each day. If you weigh 160 pounds this translates into 80 ounces or 10 cups!
Meet Your Fluid Goal
So some of you are thinking… 10 cups! That’s a lot of water. Well, the good news is that many foods and beverages contain a fair amount of water, so you don’t actually need to drink 10 cups of plain water. Beverages including milk, 100% fruit juice, herbal tea and smoothies all provide a significant amount of water. However, coffee-containing or alcoholic beverages don’t count towards your water intake since caffeine and alcohol both act as a diuretic—causing you to lose water. A good practice is to drink an extra glass of water for every cup of joe or alcohol that you consume.
In addition to nutritious beverages, a healthy way to get more water is to eat your water by including foods that have a high water content. Fruits and vegetables top the list since they contain mostly water by weight. Listed below are approximate values for water content of different foods:
Watermelon and strawberries have the highest water content at about 92%. Fruits with a water content of 80-85% include grapefruit, peaches, oranges, raspberries, grapes. Bananas are the lowest (75% water).
The foods highest in water content and lowest in calories are the non-starchy vegetables. Cucumber and lettuce top the list with 96% water. Others that contain more than 90% water include cucumbers, celery, tomatoes, cabbage, zucchini, eggplant, broccoli, cauliflower, spinach, and peppers.
Starchy vegetables and grains
Cooked starchy vegetables like potatoes and green peas have about 87% water, and white potatoes around 79% water. Grains like oatmeal and rice provide water too. Makes sense right? Think about it—when you cook them, where does all the water go?
Lean meat, fish, and poultry
Leaner cuts of protein are higher in moisture since most of the weight comes from muscle. Cooked chicken breast (without skin) and lean pork is about 75% water. Examples of water content in fish are: flounder/sole (80%), salmon (67-77%) and tuna (71%). Higher fat cuts of protein foods are lower in water. For example, 85% cooked “lean” ground beef is 60% water and beef brisket is 56% water. Bacon is high in fat and uncooked, contains about 10% water—however, water content varies greatly depending on the brand. Most bacon contains added water when it is injected with brine during the curing process. In this case, a higher water content does not make it leaner—it will just shrink more from water loss when cooked!
Cheeses are normally classified according to firmness, which varies with the degree of moisture. The moisture content of firm cheeses such as Cheddar, Edam, Gouda and Monterey Jack may be as low as 30%. In comparison, fresh cheeses—ricotta, fresh mozzarella, and cottage cheese may be as high as 80% water.
Fluids for Physical Activity
If you’re physically active, your fluid needs increase. Sweating is a double edged sword. As your core body temperature rises, the body begins to sweat. The evaporation of sweat helps to cool the body, but precious fluids are lost in the process. Drinking fluids during exercise helps to off-set fluids lost in sweat. Current guidelines suggest the following during exercise for an adult:
- Drinking about 1 cup of water 15-20 minutes before exercise
- Drink 1 cup of water every 15 minutes during exercise
- Drink 2-3 cups of water for every pound of weight you lost (by sweating) during activity
Everyone sweats differently in terms of volume and concentration. Some individuals sweat profusely; others glisten. Some people lose a lot of salt in their sweat—others do not. Tip: To estimate how much you need to drink during activity, weigh yourself before and right after exercise. The differential in weight is water loss—not fat loss (sorry J). For example, if the scale reads 175 pounds before exercise and 173 afterwards, you’ve lost two pounds of fluid needing to be replenished.
Drinking enough fluid before, during and after exercise is important to prevent dehydration. Symptoms of mild to moderate dehydration can include sticky mouth, tiredness, thirst, dry skin, decreased urination, headache, and dizziness. Symptoms of severe dehydration can include extreme thirst, confusion, lack of sweat, very dry mouth, dark yellow urine, irritability, and rapid heartbeat. Symptoms of severe dehydration require immediate immediate medical attention.
Directly or indirectly, water affects all facets of life. Without it, there would be no vegetation. There would be no oxygen for animals to breathe. Water is necessary to keep the environment and our bodies healthy.
So in addition to making nutritious food choices—don’t forget the water!