Calorie (Cal, kcal), (in nutrition) a unit, equal to the large calorie, used to denote the heat expenditure of an organism and the fuel or energy value of food. Digestive processes reduce food to usable “fuel,” which the body “burns” in the complex chemical reactions that sustain life. Also called great calorie, kilocalorie, kilogram calorie, kcalorie, large calorie. Compare calorie.
