When we talk about nutrition most people don’t consider water, in fact it is often a second thought or no thought at all.

Fat, Protein and Carbohydrates are considered macronutrients as they provide our body with energy. You can argue that water is also a macronutrient as the human body is around 55% water and needs water constantly to survive.

So, What Is Water?

Water is a liquid; the chemical formula is H2O. In case you are interested this formula simply means that two hydrogen atoms are bound to one oxygen atom. We need water to maintain homeostasis, the body’s ability to maintain a stable state. This stable state called  homeostasis is achieved through a constant transfer of fluids. The transfer of fluids takes place through osmosis, this is when the molecules pass through a membrane from one area to another.  The total amount or volume of water found in our bodies is called the “total body water”

Water is found, or divided between many areas of our body such as:

  1. Intracellular water – located within the cells of the body. Approximately 68 percent of our total body water.
  2. Extracellular water – located outside the cells. This is split further between interstitial fluid and plasma volume.
    • Interstitial fluid is located in the space between cells and makes up about 24 percent of total body water.
    • Plasma volume relates to the blood plasma in the veins and arteries. This makes up about 7 percent of total body water.

Water is moving around our bodies constantly to maintain our homeostasis

One of our key goals is to stay hydrated, particularly if we are moving and if the weather is warm!

Dehydration can be uncomfortable and even dangerous. In short our bodies use water for so many processes

  • Cellular metabolism
  • Temperature regulation
  • Solute balance
  • Transportation of nutrients
  • Cellular waste clearance
  • Maintaining homeostasis
  • Digestion
  • Balancing pH
  • Waste elimination
  • Oxygen delivery

Each of these processes is crucial for our survival and wellbeing. If we do not have enough water in our body then our major organ systems cannot be properly hydrated. We can live for several weeks without food, but only 2-3 days without water.

How Much Water Do We Need?

The National Academy of Medicine recommends the following for adult men and women.

  • Men and women consume 3.7 and 2.7 Liters per day, respectively. This is around 125 ounces for men and 90 ounces for women.

In contrast, the European Food Safety Authority recommends the following for adult men and women:

  • Men and women should consume 2.5 and 2.0 L per day, respectively.

Both of these organizations consider sources of water to be:

  • Drinking water
  • Intake from other beverages

    Food Water Sources

  • Water intake from food

But as always with any topic on heath and wellness we must remember that we are all individuals and our requirements will vary based on our diet, sodium intake, environment, lifestyle, body size just to name a few.


To make sure I get the correct level of water daily I fill up a huge water container – see the picture here. Then I sip fluid all day long. If I exercise or find myself outside for long periods in the warmth then I will drink more fluids. I find if I don’t measure out my water needs each morning and don’t keep my water container in my working space, prominently placed then I get busy and forget to drink. Making up our daily water intake in the evening can be a hard slog, plus being dehydrated can cause headaches and an unwell feeling. So stay well hydrated at all times,