Metabolism refers to all the chemical reactions occurring in the body. To maintain normal, healthy metabolism, we need inputs  such as nutrients, water, oxygen, and we need to dispose of outputs such as carbon dioxide, urine, and faeces.

We can subdivide metabolism into two types of process, catabolism and anabolism. Catabolism is the ‘breaking down’ of larger molecules into smaller ones, often with the release of energy. Anabolism is the ‘building up’ of smaller molecules into larger, more complicated molecules, often requiring the expenditure of energy.

Most of our daily energy supply comes from the food we eat. Nutrients enable the body to produce special energy-rich molecules that can be used in cells to carry out metabolic processes. The energy-rich molecule you will hear about most is adenosine triphosphate, abbreviated to ATP. This molecule powers many metabolic processes in the body.

Much of metabolism is hidden from view. However, we can monitor metabolism by measuring the inputs and outputs. This approach can be useful clinically when metabolic processes are becoming unbalanced.

If you would like to see some questions and answers on the subject of metabolism click here.