This measurement is more accurate and meaningful than GE, but is much more difficult to obtain. Heat increment is the amount of heat released during digestion and metabolism within the body. NE is actually the amount of energy used for storage, production, reproduction and work. NE most nearly approximates the true amount of energy utilized by the body. This measurement is rarely used, except for research.
All carbon compounds contain a certain amount of energy.
Each body requires a certain minimum amount of energy per day. Temperature, age and activity affect energy requirements. If energy intake is greater than use, the excess will be stored as fat. In other-words one gains fat weight. To lose a pound of fat one needs to burn about 3500 calories, beyond ones energy intake.