A unit of energy in food. 1 calorie describes the amount of energy required to raise the
temperature of 1g water by 1°C at 1atm(atmospheric pressure).
Calories are listed in the nutritional information on food packaging. Calories are usually measured in kilocalories (kcal), which equals 1000 calories, or kilojoules (kJ). 1kJ equals around 239 calories.
