What is a body actually made of?

OUR BODIES
In order to understand nutrition we need to have a bit of knowledge about our bodies and what they are made of.

To keep this simple here are the basic facts;

  • Most of the human body is made up of water (H2O) 
  • Cells consist of 65-90% water by weight. (so I am not fat, I am flooded!!) 
  • 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.
A potassium cell as imagined by MSL

0.35% - Potassium is an important electrolyte used to transmit nerve impulses and heartbeat regulation.

Now for the science. I am hoping you won’t switch off here because it’s quite interesting when you begin to delve into what and why. This foundation will also help us to understand why certain foods have amazing benefits for us. So with this knowledge in mind here is a rundown of the elements and what they do.

65% - Oxygen mixed with hydrogen gives us water (as I am sure you know). This is used to regulate temperature and osmotic pressure. Many key organic compounds consist of oxygen.

18% - Carbon. All organic molecules (fats, proteins, carbohydrates, nucleic acids) contain carbon. Carbon also is found as carbon dioxide.

10% - Hydrogen mainly exists in water, which functions to transport nutrients, remove wastes, lubricate organs and joints, and regulate body temperature. Also important in energy production and use.

3% - Nitrogen is found in proteins and in the nucleic acids that make up the genetic code.

1.5% - Calcium is used as a structural material in bones, but it is essential for protein regulation and muscle contraction.

1.0% - Phosphorus is found in ATP, which is the primary energy carrier in cells. It's also found in bone.

0.35% - Potassium is an important electrolyte used to transmit nerve impulses and heartbeat regulation.

0.25% - Sulphur found in amino acids and proteins. It's present in keratin, which forms skin, hair, and nails. It's also needed for cellular respiration, allowing cells to use oxygen.

0.15% - Sodium is an important electrolyte. Like potassium, it is used for nerve signalling. Sodium is one of the electrolytes that helps regulate the amount of water in the body.

0.15% - Chlorine used to maintain fluid balance.

0.05% - Magnesium is involved in over 300 metabolic reactions. It's used to build the structure of muscles and bones and is an important cofactor in enzymatic reactions.

0.006% - Iron is found in haemoglobin, the molecule responsible for oxygen transport in red blood cells.

Magnesium, as imagined by MSL

0.05% - Magnesium is involved in over 300 metabolic reactions. It's used to build the structure of muscles and bones and is an important cofactor in enzymatic reactions.

There are other elements found in traces, however I feel that the above is already information overload. I hope you managed to stick with it or will come back to it. As we begin to explore nutrition you will be able to link up the elements above and understand the beneficial results that you can gain from the foods available.

The information above is taken from the biochemistry module covered in lectures for the Food and Human Nutrition BSc Honours at the University of Newcastle.