Calorie

A measure of energy contained in a food or expended in exercise. Technically it's a kilocalorie, (abbreviated "kcal"), because it's exactly 1000 calories of the kind used by scientists. (A scientific calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius.) But since most people and all food labels call a kilocalorie a "calorie," Diet Power does, too.