The energy value is determined by the chemical composition of the food product, by means of the so-called. physiological equivalents energy., determining the value of metabolic energy contained in 1 g of the component. This value is converted into energy value of 100 g of product. In the conversion, the most widely used is the equivalent of Atwater: protein 400 kcal / 100 g, for carbohydrates 400kcal / 100g and the fat - 900kcal / 100g.