A calorie is the amount of heat required to heat 1 g of water from 14.5 to 15.5 °C at normal pressure. Calories are used to determine the body's energy needs and to indicate the energy content of foods. The calorific value of food is stated as kilocalories (1,000 cal = 1 kcal) or kilojoules (kJ). 1 kcal equals 4.184 kJ.
The calorific value calculation for the main nutrients and fibre is based on the following values:
Carbohydrates 4 kcal/g or 17 kJ/g, protein 4 kcal/g or 17 kJ/g, fat 9 kcal/g or 37 kJ/g, fibre 2 kcal/g or 8 kJ/g
