Pertaining to metabolism, the process by which potential energy is released from food in the human body. Metabolism includes all the biochemical reactions involved in maintaining our living cells. Metabolism is a series of chemical reactions that are in a constant state of flow between catabolism – the breakdown of molecules to obtain energy – and anabolism – the synthesis of all compounds needed by the cells. Our “metabolome” includes “both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics that are not naturally produced by an organism”.