Kilocalorie is a unit of calorie, which can indicate the amount of calorie. Card, kilocalorie are calorie units, calorie for short, English for calorie, which is defined as 1 gram of water at 1 atmospheric pressure to raise 1 degree Celsius of heat required, 1 kilocalorie is equal to 1,000 calories, about 4,186 joules. So kcal is the unit of calorie, which is mainly used to evaluate the amount of calorie intake by human body. Different foods, containing different calories, fat contains the highest calories, sugar and protein contain relatively low calories, in eating, by eating different foods, the body can take in the appropriate amount of calories, can maintain a normal metabolism, and do not take in too many calories.