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Why water is so important and how much water should you drink

During the day, we lose fluids. Therefore, it's important to drink—even if you don't feel so thirsty. So, how many glasses of water should you drink? And what if you prefer juice or fruit? When should you drink more, and why is it important not to drink too much water? Here’s a guide to maintaining proper hydration.

Water is crucial for various body processes
Water is crucial for various body processes

60% of our body is composed of water. For example, a person who weighs 70 kilograms has about 42 liters of water in their body. Water is crucial for various body processes: metabolism, the transfer of substances between body cells, maintaining the function of body cells, temperature regulation, and the transport of substances in the circulatory system.

Throughout the day, the body constantly loses fluids through urine, sweat, and even breathing. Therefore, it is crucial to drink water to prevent dehydration.

Inadequate water intake can lead to dehydration, which may manifest as fatigue, dizziness, confusion, and reduced cognitive function. Those most at risk of dehydration include young children, the elderly, and individuals experiencing vomiting or diarrhea, which cause increased fluid loss.

Water - Essential to avoid kids hydration
Water - Essential to avoid kids hydration

When the body does not receive enough water, it activates mechanisms to conserve fluids. For instance, it concentrates urine (making it darker in color, as opposed to the clear urine typically seen with adequate hydration). Additionally, the body reabsorbs more water from the digestive system and colon, resulting in harder stools and potentially leading to constipation. Therefore, sufficient water intake is essential for the proper functioning of the digestive system, softening stools, and preventing constipation.

The consequences of inadequate water consumption are not only short-term. Epidemiological studies indicate a chronic low water intake is associated with obesity, kidney stones, and diseases such as cardiovascular diseases, diabetes, and cancer. Thus, it is important to maintain adequate water consumption to support overall health and proper bodily function in both the short and long term. Additionally, water contains small amounts of essential minerals like magnesium, iron, zinc, and calcium. While most minerals are obtained from food, water also contributes a small amount.

Each of us is unique, and so are our body's fluid requirements. There are two main approaches to estimating the amount of fluids we need, and ultimately both provide similar recommendations:

  • "Replacements": This approach is based on the amount of fluids that need to be replaced in the body due to daily loss. Our body loses about one and a half liters of fluid through urine and an additional liter through breathing, sweat, and stool. Food provides approximately 20% of our fluid intake, so we need about 2 more liters from beverages to make up for the lost fluids.

  • Dietary Reference Intakes (DRIs): These recommendations are based on the average intake of healthy individuals aged 19 to 30. According to these guidelines, women should consume 2.7 liters of water per day, and men should consume 3.7 liters per day.

How is it so much? Let us explain.

The food we eat (such as vegetables, fruits, and yogurt) and the beverages we drink (such as tea, coffee, juice, and water) all contribute to our fluid intake. Food accounts for about 20% of our total water consumption.

How Much Water Should You Drink Daily?

How much water should you need to drink
How much water you need to drink daily?

In summary, according to the DRIs (Dietary Reference Intakes), women should consume about 9 cups (approximately 2.2 liters) of fluids daily, while men should aim for about 13 cups (approximately 3 liters).

What's New?

Scientists now recommend considering all sources of fluids from food, not just water. Therefore, people who consume a lot of fruits, vegetables, yogurt, etc., might need to drink less water.

Foods High in Water Content

Fruits rich in water
Fruits rich in water

Fruits and vegetables such as watermelon, melon, strawberries, lettuce, cabbage, and celery are rich in water. (Note: Diabetics should consume fruits in moderation.)

When to Increase Your Water Intake

It's important to drink more water in the following situations:

  • If you have kidney stones.

  • During illness or high fever, which increases fluid loss through sweating and breathing.

  • After vomiting or when suffering from diarrhea.

  • If you have recurring urinary tract infections.

  • During intense physical activity.

  • In extreme weather conditions (hot or cold). For example, in winter, a heated room can cause significant fluid loss through breathing even if you don't feel it.

  • During pregnancy.

  • While breastfeeding.

Water Intake During Pregnancy and Breastfeeding

Pregnant and breastfeeding women should drink more
Pregnant and breastfeeding women should drink more

  • Pregnant women should add 2 extra cups of fluids daily to the recommended amount, totaling about 11 cups daily.

  • Breastfeeding women should add 4 extra cups of fluids daily, totaling about 13 cups daily.

Water Intake During Exercise

There are two recommendations for hydration during or after exercise:

  1. One cup of water for every kilometer run.

  2. Two to four cups of water for every hour of exercise, depending on intensity and temperature.

What Happens If You Drink Too Little Water?

Drinking too little water can lead to dehydration.

How to Know If You're Drinking Enough Water

One way to ensure adequate hydration is by observing your urine. Light-colored, odorless urine indicates proper hydration, while dark, strong-smelling urine suggests you need to drink more water.

What Happens If You Drink Too Much Water? What is Water Intoxication?

In Israel's climate, high water intake is necessary to compensate for sweat loss. However, overdrinking can be harmful, especially for individuals with kidney or heart failure. Excessive drinking can also harm healthy individuals by disrupting the salt balance in the body. Overhydration symptoms can mimic dehydration, including confusion and seizures.

Water intoxication occurs when excess water dilutes sodium in body fluids (like blood), leading to hyponatremia. Mild hyponatremia can cause nausea and vomiting, while severe cases can result in headaches, drowsiness, seizures, and brain swelling. Water intoxication is a medical emergency that can cause severe bodily harm or death if untreated.

Extreme cases can occur in individuals using ecstasy, which affects the brain's thirst center, causing extreme thirst despite adequate hydration. Uncontrolled drinking in such situations can lead to water intoxication.

While no upper limit for water intake is set, drinking large volumes in a short time (over 700 milliliters to 1 liter per hour) can harm kidneys and other body systems. Recommendations vary by individual body size, with smaller individuals at higher risk of water intoxication and larger individuals needing more water.

Water or Juice: What's Better and When?

Daily fluid intake can include juices, soft drinks (note that sugary drinks add unnecessary sugars), milk, and tea, but water remains the best, calorie-free choice.

A good way to distribute fluid intake throughout the day is to drink one cup of water with each meal and another cup between every two meals (assuming three main meals and two snacks per day).

If your health is normal, an extra cup of water won't harm you. To ensure adequate hydration, it's recommended to carry a reusable water bottle, which is healthier and more environmentally friendly.

What If I Don't Like the Taste of Water?

How to make water tastier
How to make water tastier

If you find water unappealing, try these tips:

  • Add a slice of fresh fruit like apple wedges, strawberry slices, or peach slices to your water. A bit of lemon juice or an orange wedge can also help.

  • Herbal teas (hot or cold) can substitute for water between meals. Timing is important because strong herbal teas with meals can interfere with the absorption of minerals like calcium, iron, and zinc.

  • Plain sparkling water (without added flavors or sweeteners) is a good alternative.

  • Limit diet drinks to 2-3 cups per day, including artificially sweetened hot beverages.


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