Every gram of fat produces 9 calories, so if you want to reduce 1 kg of fat, from a medical point of view, you must consume 7700 calories. If you reduce 500 calories a day.

Reduce 1 kg requirement 14 days; If you reduce 1000 calories a day, it will take seven days to lose 1 kg and seven days to lose 1 kg. However, people have metabolism every day and must have the most basic calorie intake to maintain the needs of the body. Generally speaking, boys need 1600 calories a day and girls need 1200 calories.

Extended data:

Calorie (Cal for short), transliterated from English Calorie, is defined as the heat required to raise 1 gram of water to 1 degree Celsius at 1 atmospheric pressure; Calorie is an energy unit, which is still widely used in nutrition measurement and fitness manual. The international standard unit of energy is joule. As the legal unit of food calories, joules are widely used in Europe, while calories are used in the United States. Although Joule is the legal unit in Chinese mainland and Taiwan Province Province, it is still widely used in Chinese mainland and Taiwan Province Province because of tradition.

Reference: Baidu Encyclopedia-Calories