Calories

Excerpt

Calories are a measure of energy. "Small" calories (cal) estimate the amount of energy required to raise the temperature of exactly 1 gram of water by 1 degree Celsius at 1 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 equals 1,000 of the small calories (1 kilocalorie).