GENERAL CONSIDERATIONS: Food provides energy and building material for countless substances that are essential for the growth and survival of every human being. To address nutrition, we must consider at least an overview of digestion, absorption, transportation, and excretion of nutrients at every system's level. These processes convert complex foodstuffs into individual nutrients ready to be used in metabolism. Proteins, fats, and carbohydrates each contribute to the total energy pool, but ultimately the energy they yield is available for the work of the muscles and organs of the body. The way nutrients become integral parts of the body and contribute to proper functioning depends heavily on the physiologic and biochemical processes that govern their actions. It is now known that these metabolic processes are altered in the presence of acute and chronic inflammation.