Water Defined 

Question: Does water provide energy to the body? 

Answer:  No.  Water serves a number of functions in the body - providing it with energy is not one.  There are zero calories in water (H20).  Calories provide energy to the body.  However, water does play a key role in the generation of energy for the body.  It is essential for life.  The body is made up of 70% water and a human body will not survive without water consumption longer than 3-5 days.  However, it can survive 20-40 days without food intake.  That is because water and food are stored in very different ways within the body.  Food is metabolized and used by your body as energy via 5 of the 6 essential nutrients for survival:  (1) carbohydrate,  (2) protein,  (3) fats, (4) vitamins, (5) minerals.  Water (6) helps distribute these metabolized nutrients to cells in your body. Water is life and essential to it thus, making it a nutrient.  However, it does not, in itself, provide the body with energy.  It only breaks down and delivers nutrients to cells in the body that provide it (the body) with energy.  

The following are the 5 basic functions water plays in our bodies: 

1) Cell life

2) Chemical and metabolic reactions

3) Transport of nutrients

4) Body temperature regulation

5) Elimination of waste

Cell life - water carries and distributes nutrients to cells in the body.  For instance it carries vitamins, minerals and glucose to

Chemical and metabolic reactions - water removes waste products including toxins that the organs' cells reject and removes them through urine and feces.  

Transport of nutrients - water participates in the biochemical breakdown of what we eat.  What dilutes and distributes nutrients to cells in our body.  

Body temperature regulation - water has a large heat capacity which helps limit changes in body temperature in a warm or a cold environment.  Water allows the body to release heart when ambient temperature is higher than body temperature.  The body begins to sweat and the evaporation of water from the skin surface cool the body.

Elimination of water - water is an effective lubricant around joints.  It also acts as a shock absorber for eyes, brain, spinal cord and even for the foetus (fetus) through amniotic fluid.  

Source: Montain et al. (1999)

Water can be ingested into the body through foods as well as by itself.  As much as 33 oz (1 liter) of water is consumed via solid food, and 33 oz - 99 oz (1 - 3 liters) as fluids drunk.  Many authorities recommend 8, 8 oz glasses of water should be consumed each day.  64 oz.  Know that water is also formed in the body as a result of oxidation of macronutrients, but the water thus obtained usually constitutes less than 10 percent of total water in the body. 

Our skin and organs are all made-up of water.  When we eat, breathe, and use our muscles, our body creates residue waste products that the body has to get rid of. Good clean water helps us do this. Without enough water we do not get rid of these waste products.  The waste products that we do not discard are stored in our body.  This is not good and makes the lack of proper water ingestion closely connected to fat gain.  Proper intake levels can equally equate and contribute to fat LOSS. Furthermore, water helps the body metabolize stored fat because, for instance, the liver, which metabolizes fat, becomes overloaded when the kidneys don’t get enough water. Your liver’s fat processing function is compromised when it has to do the kidneys’ job as well. Water also helps suppress appetite and relieve fluid retention problems.

Source: Dragonbooster, Yaohoo.com

You can think of water as being kind of like oil to a car's engine.  The car requires gasoline to operate.  However, without the oil, the parts of the engine won't move properly.  Similarly is the function of water in the body.  Food would equate to gasoline in this context.  So, although water does not provide energy to the body, per se, it is tantamount to its daily function.