Calories (calories for short) are defined as the heat required to raise 1 gram of water 1 degree Celsius at 1 atmospheric pressure. It is still widely used in nutrition measurement and fitness manual. The international standard unit of energy is joule.
Calories, also known as the capital letter C, are most commonly used in food labels, which is equivalent to the heat required to raise 1 000 grams of water from 14.5 degrees Celsius to 15.5 degrees Celsius at1atmospheric pressure, which is about equal to the internal energy of 4 186 joules. Small card, also known as cal, is common in scientific research literature, 1000 small card = 1 big card.
Extended data
Need heat
Daily calorie requirement of adults = basic calorie required for basic metabolism of human body+calorie required for physical activity+calorie required for digestion of food.
Heat required for digesting food = 10% x (minimum heat required for basic metabolism of human body+heat required for physical activity).
Daily caloric requirement of adults = 1. 1 x (minimum basal caloric requirement for basic metabolism of human body+caloric requirement for physical activity).
Male: 9250- 10090 kJ. Female: 7980-8820 kJ.
Note: The daily calories provided by food should not be less than 5,000-7,500 kilojoules, which is the least energy to maintain normal life activities.
Baidu encyclopedia: calories