Energy Balance

Energy balance is defined as a balance exists between the energy taken in as food and the various energy forms used by human. If the energy balance is perfect, the weight will remains constant. If the energy taken excess the energy expenditure, it will stored in the body in form of fat. Energy intake less that energy used and the difference is made up by burning fat in body.

Organism’s source of energy is chemical energy supplied by foods where the oxidation of foodstuff provides chemical energy for cellular reactions. When nutrients are broken down, about 40% is captured in form of ATP.

Energy in nutrition is defined as the amount of heat necessary to raise temperature of one kilogram of water to one degree Celsius. Measurement of energy expenditure can be done using direct calorimeter or indirect calorimeter.

Direct calorimeter is the direct measurement of the actual energy expended by the body throughout a given period. The heat given of by the human subject in a special calorimeter is absorbed by the water in the coils surrounding the well-insulated chamber. Thus, the total heat may be measured directly.

For the indirect calorimeter, the rate of metabolism or heat production is calculated through the oxygen intake and carbon dioxide content of the expired air as measured by a respiration apparatus. This may apply to various type of activities or when lying at rest.