Energy Balance

When any fuel is burned, it consumes oxygen and liberates heat. The 'burning' of food fuels by our cells is no exception. Energy can be neither created nor destroyed - only converted from one form to another. If we apply this principle - the first law of thermodynamics - to cell metabolism, it means that bond energy released as foods are catabolized must be precisely balanced by the total energy output of the body. For this reason, a dynamic balance exists between the body's energy intake and its energy output.