A calorie is the amount of energy that is released as heat when food is metabolized. Scientists determine the number of calories in foods by burning them in a laboratory device called a calorimeter and measuring the amount of heat produced. The calorie is the amount of heat necessary to raise the temperature of one liter of water one degree Celsius. |Carbohydrates| and |protein| contain four calories per gram; fat contains nine calories per gram, and |alcohol| seven calories per gram. Multiply your ideal weight by 15 to determine daily calorie intake if you are moderately active.
