Water for sustenance and maintenance

Pure water is the world’s first and foremost medicine.

Water is required for various bodily functions to keep our organs and metabolism going smoothly.

There ways by which our body maintains an equilibrium with the intake and loss of water.

The amount of water lost needs to be replaced with the equal intake of water to help continue all the important functions in the body.

Not only the metabolic functions, water has been known to aid in various other processes.

  • Water helps in digestion, absorption and elimination of toxins from our body.
  • Water that we drink, water content of the food, breaking down of nutrients contributes to the total water intake while the water is lost through urine, sweat, faeces and respiration.
  • Proper hydration improves cognitive function and physical endurance, helps to lose weight and prevent diseases.


Water is an essential element of our life. 70% of the human body is composed of water and is required in all the biochemical and physiological process in our body.

proverb on water

Even though a lot of emphasis has been placed on the sufficient intake of water from the earlier times, there still seem to be some neglect and a bit of ignorance with respect to the quantity of water to be consumed.

Too much of information on the media has distorted many facts and has led to the confusion in the correct approach to drink water. In this article we will be discussing on the function of water in our body, best way to drink water, the right quantity and the right time to drink water.


What role does water has in our body?

Functions of water 

Basic constituent

Water is present in each and every cell, tissues and compartments acting as a building material. This is apparent from the fact that the water needs are higher during the growth phase of our body.

As a solvent

Water acts as a solvent for various biochemical reactions that take place in our body especially during digestion and breakdown of macronutrients. Many of the vitamins are soluble in water and it helps in the absorption of the nutrients.

Acts as a carrier

Water helps in the transport of nutrients and wastes to and from the cells respectively. It maintains vascular volume and help in blood circulation. All the major systems like respiratory, digestive, reproductive, nervous, brain, liver, kidney all depend on water for their smooth functioning.


Water has a large heat capacity, which contributes to limiting changes in body temperature in a warm or cold environment. Loss of water through the skin during sweating helps to lower the body temperature, is a good example to show that water aids in thermo regulation.

As a lubricant and shock absorber

Water along with other constituents act as a lubricant for the joints, is a constituent of saliva which aids in digestion. By maintaining the cellular shape, water also acts as a shock absorber during walking or running. This function is important for the brain and spinal cord, and is particularly important for the fetus, who is protected by a water cushion.


Sources of water intake

We get water through various sources like -

  • Food - which constitutes 25-30% daily water intake. This is however variable due to dietary habits
  • Metabolic water - water which comes from breakdown of nutrients or rather water released on oxidation of food like 100g of starch gives 60ml of water, 100g of protein gives 40 ml and 100g of fat gives 107 ml of water. These sources contribute only 10% of the total water input.
  • As liquid water - consumption of 1-2 liters of water again depending on the climate, activity level, age, habit. This intake is usually governed by the thirst mechanism.


How is water lost from the body?

There are various ways by which we lose water from the body.

  1. Loss of water from skin and during breathing, also called transpiration. This loss is influenced by temperature and humidity.
  2. Loss of water through sweat. This loss can be as minimal as 200 ml in a cool climate to as high as 4 litres in a hot environment.
  3. Loss of water through faeces, which is minimal - 100 to 200 ml but this loss can increase upto 5 litres during diarrhoea or dysentery.
  4. Loss of water in urine which is the major route of excretion. It averages from 1-2 litres per day in an adult.


Why is sufficient hydration necessary?

Research shows multiple health benefits of consuming sufficient quantity of water.

  • Helps to lose weight

Studies3 have found that drinking water before a meal help to reduce the intake of food and consequently reduce the amount of energy uptake. This is believed to prevent obesity and help to reduce weight in obese people.

One study5 showed that dieters who drank 17 ounces (500 ml) of water before each meal lost 44% more weight over 12 weeks, compared to those who didn’t.

  • Improve energy levels and brain function

It has been observed that if you don't stay hydrated throughout the day, your energy levels come down and the brain function also suffer. This has been supported by various studies, One study in women showed that a fluid loss of 1.36% after exercise impaired mood and concentration and increased the frequency of headaches4.

  • Effect on the physical activity

Physical activity results in increased water requirement. Mild dehydration can negatively impact the physical performance. Hence for people involving in high intensity work out or athletes should keep themselves well hydrated.

  • Help in preventing health problems

Drinking sufficient quantity of water helps to keep numerous health issues at bay. Proper hydration prevents constipation by helping to digest the food and makes it easier for the elimination. Water also removes the toxins from the body by flushing it through urine and thereby preventing kidney stones.

Studies also suggest that sufficient hydration to the skin aids in wound healing.6 The discovery that a moist environment actively supports the healing response when compared with a dry environment highlights the importance of water and good hydration levels for optimal healing.

  • Best anti-aging remedy

Sufficient hydration preserves the elasticity of the skin and thereby prevent wrinkles at an early age.


3 https://doi.org/10.1111/j.1753-4887.2010.00311.x

4 https://www.ncbi.nlm.nih.gov/pubmed/22190027

5 https://www.ncbi.nlm.nih.gov/pubmed/19661958

6 J Wound Care. 2016 Mar;25(3):122, 124-30.

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