Kilojoule is a unit of heat, and now kilojoule is often used to measure the heat contained in food and the heat consumed in a certain exercise unit time. Calories, also known as kilocalories, are also units of heat, which are mostly used in nutrition measurement and health manuals. 1 kcal = 1000 kcal, the international standard energy unit is joule, 1 kcal =4. 186 kj, while 1 kilojoule = 1000 kj, so one kcal = 4 .. At present, people often use the number of calories or kilojoules consumed to control the calories of food intake and exercise consumption, thus controlling weight.