Calories

Excerpt

Calories are a measure of energy. "Small" calories (cal) estimate the amount of energy required to raise the temperature of exactly one gram of water by one degree Celsius at one atmospheric pressure, and “big” calories, also known as kilogram calories (Cal), are more commonly known and refer to the calories in food. The big calorie is named because it is equivalent to 1000 of the small calories (1 kilocalorie).