Understanding Water Balance in the Human Body: A Biochemical Analysis

The biochemical composition of the human body is nearly 70 percent water, on average. Water in the body either can exist on its own or can be found in human fat, which holds a fair amount of body water.

Fundamentals

• According to "Netter's Atlas of Human Physiology," the two fundamental breakdowns of biochemical water in the body are intracellular fluid and extracellular fluid.

Water vs. Fat

• To analyze and understand the proper amount of water in your body, you must first know how much body fat you have. These measurements vary between men and women, and when biochemical water is being calculated, only water alone is being measured, and not the water in fat.

  Lisa Shea, the Low Carb Editor of BellaOnline.com, provides a good example to clarify: "If you have 33 percent fat in your body, then you only need another 37 percent of water alone, because you have water in the fat. The scales don't count 'fat water' as water [itself], otherwise your numbers would get very confusing."

Loss and Replenishment

• If you lose weight, you'll need to replenish more of your body water through consumption. When the body has too much water, it's eliminated through urination, as well as by perspiration when the body is exerted physically.

Dehydration

• According to the Mayo Clinic, dehydration occurs when the body loses more water than it's taking in. Excessive perspiration as well as illness -- such as diarrhea, vomiting and fever -- can lead to dehydration. Dehydration is a concern among children, the elderly and the chronically ill, and symptoms include dry mouth, thirst, headaches, dizziness and constipation.