Proper Hydration: Why It Matters

Water is a key element of every cell in the body. In a newborn baby, the body's water volume is about 90%, highlighting its importance for vital processes. As we age, the body loses moisture, and in old age, the proportion of water in the body decreases to 60%.

Water performs numerous vital functions:

• Delivers nutrients and oxygen to cells;
  
  
• Helps regulate body temperature;
  
  
• Moisturizes inhaled air;
  
  
• Participates in converting food into energy.

Unfortunately, people often do not think about replenishing their water balance daily.

The Myth of Two Liters a Day

For a long time, it was believed that a person must drink at least two liters of water daily. However, studies by the World Health Organization have called this assertion into question. Daily fluid needs depend on weight, age, physical activity, and environmental temperature.

How Much Water Should I Drink per Day?

A baby weighing no more than 10 kg needs about 4 ml of water per hour. For children weighing up to 20 kg, the requirement is between 1 to 1.5 liters per day. For individuals weighing over 20 kg, the calculation is made using the formula: 1.5 liters for the first 20 kg of weight plus 20 ml for each kilogram above that.

For example, a person weighing 70 kg should drink:
1500 ml + (70-20) * 20 ml = 1500 ml + 1000 ml = 2500 ml of water per day. 

We can use this formula to determine who fits the widespread recommendation of drinking two liters daily. Subtracting 1500 ml from 2000 ml (the difference is 500 ml) and dividing by 20 kg gives us an additional 25 kg. Adding that to 20 kg results in 45 kg.

Therefore, two liters are sufficient for individuals weighing up to 45 kilograms, such as teenagers or very petite women.

This formula helps identify basic water needs, but individual characteristics of the body, air temperature, level of physical activity, dietary habits, and health status can introduce variability. Each person should adjust their fluid intake according to their needs.

When the Body Needs More Water

We drink when we feel thirsty-a signal that the body is lacking about 1% of its water. Hot weather, physical exertion, and consumption of spicy or salty foods accelerate fluid loss; therefore, it is necessary to replenish hydration. 

Daily Hydration Routine

Knowing how much water to drink and how to distribute it properly throughout the day is important. Drinking the daily norm in one or two sittings can overload the kidneys.

On an empty stomach, the body absorbs about 300 ml of water within 15 minutes, while on a full stomach—no more than 800 ml per hour. 

• In the morning, drink a glass of water on an empty stomach to kickstart your metabolism and "wake up" your body.
  
  
• During the day, drink water 2-3 hours after meals.
  
  
• In the evening, add another glass of water 2-3 hours before bedtime.

With five meals a day, one can drink about seven glasses of fluid daily, corresponding to approximately 1700-1800 ml. The rest comes from food.

Hydration Rules

• Water should be warm; cold liquids irritate the stomach lining, while hot ones can raise blood pressure.
  
  
• It is better to drink in small sips.
  
  
• If you feel hungry—first drink some water since thirst is often mistaken for hunger.
  
  
• Some specialists advise against drinking while eating so as not to dilute gastric juices with water; others believe drinking is acceptable as long as it does not interfere with digestion.

Conclusion

An optimal hydration routine throughout the day is key to health and longevity. Consider individual needs and remember that water is fundamental to all vital processes.