WHY DOES FOOD BURN WHEN WE TAKE IN OXYGEN?

Oxygen Required for Metabolism

Metabolism is a generic term for all the chemical reactions that break down or "burn" food to provide energy for the operation of an organism. The word "burn" is used advisedly, because the energy yield from a food in the human metabolic process is comparable to the energy obtained by actual combustion.

Like ordinary combustion, the metabolism of food requires a supply of oxygen and produces carbon dioxide as a combustion product.