The name calorie is used for two units of energy.
● The small calorie or gram calorie (symbol: cal) is the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere.
The large calorie, kilogram calorie, dietary calorie, nutritionist’s calorie, nutritional calorie, Calorie (capital C) or food calorie (symbol: Cal) is approximately the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius. The large calorie is thus equal to 1000 small calories or one kilocalorie (symbol: kcal).
Although these units are part of the metric system, they have been superseded in the International System of Units by the joule. One small calorie is approximately 4.2 joules (so one large calorie is about 4.2 kilojoules). The factor used to convert calories to joules at a given temperature is numerically equivalent to the specific heat capacity of water expressed in joules per kelvin per gram or per kilogram. The precise conversion factor depends on the definition adopted.
In spite of its non
Calories do count.
Regardless of the debate, keeping track of the calories in is really important. If you don’t know where your calories are coming from, you can’t adjust your intake.