ABSTRACT
To assess food energy intake, one must make a complete and detailed record of all the foods and liquids consumed in addition to providing a description of how the food is prepared. However, when one is interested in the whole body, not just a particular cell, one views the energy equation in different terms that describe the losses of energy from the food as it passes from the dinner plate into the body and its metabolic end products are excreted. The measurement of energy need based on energy lost as heat or on the consumption of the oxygen needed to oxidize fats, carbohydrates, and proteins to provide this energy has been well studied. Few clinical settings can afford the time and expense to assess energy need in this way. The heat produced through this oxidation is needed to keep the body warm, but it is also a measure of the energy need.
