Kilocalorie
The term used to represent the amount of energy required to raise the temperature of a liter of water one degree centigrade at sea level.
In nutrition terms, the word calorie is commonly used to refer to a unit of food energy.
(The word calorie is used instead of the more precise scientific term kilocalorie.) Technically, however, this common usage of the word calorie of food energy is understood to refer to a kilocalorie (and actually represents, therefore, 1000 true calories of energy).