Food energy is the amount of energy in food.
Food energy is typically measured in units of calories, although the International System of Units unit kilojoule (1000 joules) is becoming more common. Some types of food contain more energy than others, fats and sugars have particularly high food energy levels.
Note that the "calorie" used by dieticians for food is actually a kilocalorie, or 4,186 joules.
See also