How Much Water Should You Drink A Day? – Customize Your Daily Intake

Water plays an essential role in our physiological, mental and emotional health. However, both insufficient or excess water intake can be detrimental to our health. How much water to drink a day is a simple question lacking an easy answer. Seems like a law of nature that too much or too little of anything is not good. Let’s examine how to find the balance.

Calculators and recommendations

Daily water intake calculators can provide a generalized guide that is easy to remember such as the 8×8 guide (8 glasses of 8 ounces per day) recommended by many health authorities.

The Institute of Medicine recommends a total daily water intake of 91 ounces (2.7 liters) for women and 125 ounces (3.7 liters) for men from all beverages and foods.

Many recommendations serve well as a guideline, but they only use a few variables such as body weight, activity level and caloric intake. There are many other important factors to consider when evaluating your own optimal daily water intake. Let’s take a look at them.

Factors influencing your daily water needs

Age

As we age, our sense of thirst also decreases which needs to be considered to avoid dehydration. On the other hand, changes in kidney function occurs with age resulting in a decreased ability to conserve sodium. In which case there is a risk of overhydration.

As we grow older, and especially after the age of 60, it would be ideal to ensure sufficient water intake by establishing a schedule for drinking fluids to reduce any risk of health issues. 

Level of activity

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Sweat lost from any type of activity needs to be replenished with water. As you sweat you also lose minerals (electrolytes). It is recommended to either add electrolytes to your plain water, or consume a sports drink.

How much water to drink depends on the duration and intensity of the activity. A general guide would be to consume 40 ounces (1.2 liters) for every hour of activity where you are sweating.  

Whether it’s a gym workout, a sports game or training exercises, it is ideal to drink water before, during and after the activity to ensure you are not dehydrated.

Environment

Hot and humid climates can cause you to sweat at a higher rate than usual. High altitudes in excess of 8,200 feet (2,500 meters) can cause rapid breathing and increased urination.

Since these factors can affect your rate of body fluid loss throughout the day, it is important to compensate for this loss of fluid by consuming water periodically during the day instead of consuming large amounts of water all at once.

A general guideline is to increase your daily water intake by 20% under these environmental conditions.

Health condition or illness

There are several factors that can make your body retain water or interfere with the ability to excrete water. These include conditions involving thyroid, kidney, liver, adrenal or heart problems.

Pain medications, anti-inflammatory and certain antidepressants can also be contributing factors in water retention. In this case, it is recommended to be cautious of excessive fluid intake.

Other conditions such as fever, diarrhea, urinary tract stones, bladder infections, gout and constipation may require you to increase your fluid intake to replenish additional fluid loss or shortage of fluid in your body.

Diuretic drugs used to treat high blood pressure can also increase water loss and should be considered when evaluating your daily water intake. Since the degree of these conditions may vary, it would be wise to always consult with your physician on your daily water intake needs.

Pregnancy or breast-feeding

During pregnancy or breast-feeding, it is suggested that women increase their water intake to ensure they are well hydrated. According to the Institute of Medicine, the suggested median consumption of fluids by pregnant women is 78 ounces (2.3 Liters) and 105 ounces (3.1 liters) for women who are breastfeeding.

Contrary to common belief, drinking more water than needed does not increase milk production and vise versa – restricting water intake does not reduce milk production. For the busy mother it is advised to keep a filtered bottle of water or beverage handy at all times to ensure fluid consumption is adequate throughout the day.

Stress

We all know that stress is detrimental to our health, and it also affects our level of hydration. High levels of stress can weaken your adrenal glands which are responsible for regulating both salt and water in your body.

If you are under a prolonged duration of stress, your entire body and cells become depleted from water resulting in dehydration. It is advised to be more conscious of your water intake and consume fluids throughout the day. However, the cause of your stress eventually needs to be addressed to maintain your well-being.

Diet

Something to keep in mind is that thirst and hunger signals can sometimes be easily confused. Because the same part of your brain is responsible for interpreting both feelings, a feeling of hunger between meals can potentially mean that your body needs more water. 

Being more conscious about how you feel and your eating habits will serve you well. 

Diuretic foods and drinks

Diuretics are substances that cause your body to excrete more water through urine. Although diuretics mainly get rid of excess water in the body, if you encounter yourself eating or drinking many diuretic foods, it would be ideal to ensure you are having sufficient water to replenish your body.

Below is a list of common diuretics that you may find yourself consuming on a regular basis:

• Coffee
• Green or black tea
• Parsley
• Cabbage
• Asparagus
• Beets
• Celery
• Garlic

Sodium

Foods that are high in sodium can cause your body to retain more water, making you thirstier. Drinking more fluids will ensure you regulate the motion of fluids in your system.

Protein

Your daily protein intake can also affect the amount of fluid held in the blood. According to a study conducted by the University of Connecticut, if you are consuming large quantities of protein, you need to increase your water intake regardless of whether or not you are feeling thirsty.

Increasing your water intake will ensure proper protein excretion by the kidneys and prevent dehydration.

Carbohydrates

Carbohydrates cause our body to retain water and sodium. If you are following a low-carb diet or the Ketogenic diet, your body can no longer retain water as in the case with a regular diet.

It is very important to consume more water on a daily basis to compensate for the lack of water retention and ensure you are never dehydrated.

Alcohol

Similarly, alcohol has a temporary diuretic effect. The higher the alcohol content consumed, the more water the body loses.

To counter these diuretic effects, it is a good idea to drink water when consuming alcoholic beverages, especially ones with high alcohol content such as vodka and whiskey.

Herbal supplements

Similar to some medications discussed earlier, herbal supplements such as those targeting weight loss or reducing bloat can impact your body’s water balance. Keep in mind that water weight lost can actually be harmful, and some of these weight loss herbal supplements work as laxatives, while others work as diuretics.

If you are consuming any supplements of that nature, make sure to stay hydrated throughout the day.

Sources that count towards your daily water intake

Plain drinking water is not the only source of fluid for your body. All beverages and foods you eat have varying amounts of water that your body absorbs. From your morning coffee or tea, to meat, fish, fruits and vegetables – they are all sources of water that contribute to your daily intake.

When it comes to fruits and vegetables, many are over 90% water by weight. Moreover, water is also produced when your body metabolizes the food you eat.

Many reports on water intake do not account for water obtained from these alternative sources, and it’s a good idea to gauge the type of diet you have and how much water-rich foods you eat. To give you a general idea, below is a table with common foods and their percentages of water content:

Dehydration

Dehydration occurs when the loss of body fluids outweigh the intake. When this occurs, your body does not have enough fluids to optimally perform its basic functions such as detoxification, lubrication, digestion, and many more vital to your health.

Fluid loss can occur gradually if your water intake is insufficient through a prolonged period of time, or it can happen rapidly for example while exercising. Severe dehydration can be very detrimental to your health, so it is best to understand the early signs of dehydration. Let’s take a look at them.

Signs of dehydration

Thirst

Well, this one is obvious. If you are feeling thirsty, you are already dehydrated.

Hunger

As mentioned before, both hunger and thirst cues can be confused sometimes. If you are feeling hungry between meals, it may be a signal that your body needs more water. Alternatively, you can eat water rich fruits and vegetables.

Panic attack signs

It is sometimes possible for early signs of dehydration to mimic signs of a panic attack. Dehydration causes your blood pressure to drop, as a result your heart rate increases which causes dizziness.

If you do not usually experience anxiety, these symptoms may simply mean that you need a glass of water. And if you do, rehydrating your body may prevent it developing into a panic attack.

Headache

An unexpected headache can mean that your brain is not getting enough oxygen due to lowered blood volume, which can occur if your body is dehydrated.

General dryness

Any excessive signs of dryness in the body such as dry mouth or chapped lips. Some people normally have dry skin, even more common for most people in winter. But if your skin is flaky or cracked then it is dehydrated, not just normally dry.

Muscle cramps and spasms

When your body is dehydrated, it starts pulling fluids from other parts of the body causing the blood to thicken. Cramping muscles are a sign that blood carrying oxygen and proper nutrients is not reaching the muscles in time.

Bad breath

Your saliva has antibacterial properties. When your body is short on water, your saliva levels drop and are no longer able to fight those odor-causing bacteria.

Constipation

If you are regularly constipated, it is because your body needs more water and is pulling excess fluids from your stool making it harder to travels through the colon.

Urine color

Although not precise due to many factors affecting it, urine color can serve as a crude indication of hydration status. Factors such as diet, medications, supplements and vitamins can all greatly affect urine color. I know not to use it as a measure when I take my multivitamin.

Here is a urine color visual reference:

Signs of severe dehydration

• Rapid breathing or heartbeat
• Fever
• Confusion or lethargy
• Sunken eyes
• Skin pinch takes more than two seconds to bounce back

Severe dehydration is a serious condition as should be treated immediately by seeking professional medical help.

A study conducted by the University of Nebraska gives us insight into the levels of fluid loss and their corresponding signals.

• 1-2% body weight fluid loss = thirst
• 3% body weight fluid loss = dry mouth
• 4% body weight fluid loss = work capacity decreases by 20-30%
• 5% body weight fluid loss = headache, lack of concentration and sleepiness.
• 6% body weight fluid loss = tingling sensation and/or numbness of extremities
• 7% body weight fluid loss = collapse, unconsciousness
• 10% body weight fluid loss = life-threatening situation
  

How to avoid it

The best way to ensure you stay sufficiently hydrated is to consume fluids throughout your day and avoid any of the dehydration signs we just covered.

Here are some tips that you can easily add to your lifestyle,

Overhydration

Over hydrating can cause water intoxication and can be very detrimental to your health. The condition is called hyponatremia, and it happens when your kidneys cannot excrete excess water. Sodium levels in the bloodstream turn extremely low causing your cells to become water saturated.

Although rare, it is a good idea to familiarize with the signs and how to avoid them. Especially if you practice endurance sports or intense exercises.

Signs

Some signs of water intoxication can be quite extreme while others may mistakenly seem to be unrelated. They range from nausea and irritability to feeling lethargic or confused. And extreme cases can result in seizures or a coma.

How to avoid it

It is always a good idea to consume water periodically rather than chugging large quantities, even if you are very thirsty during your exercise or endurance sport.

Since water intoxication is caused by the dilution of electrolytes (minerals), it is probably best to drink water with electrolytes if you are consuming large quantities at a given time.

Final Thoughts

Recommended daily water intake serve only as guides because there are many factors that can alter your body’s optimal fluid requirements. 

The most important things to consider are to:

• Listening to your body will give you early signs of dehydration. 
• Consume fluids throughout the day rather than lots of it in one sitting. 
• Adopting some simple lifestyle changes can ensure you are well-hydrated. Like drinking a filtered glass of water during every meal, or every time you urinate.
• Be conscious of how much water your body is losing . If you are sweating, replenish these lost fluids.