Calories: Calories (cal for short) are an energy unit, which is defined as the heat required to raise 1 gram of water 1 degree Celsius at 1 standard atmospheric pressure. As the legal unit of food calories, like Joule, calories are widely used in Chinese mainland and Taiwan Province. Although the official definition is clear, because the measurement of "calories" is too small, at present, kilocalories (commonly known as calories) are widely used in nutrition, and abbreviated as "calories".
For every 100 calories consumed, you need to do one of the following exercises to finish it: going up the stairs for 7 minutes, going down the stairs 14 minutes, mopping the floor for 20 minutes, sweeping the floor for 25 minutes, shopping for 33 minutes and jogging for 20 minutes.
1 kcal = 1 kcal = 1000 calories = 1000 calories
1 g carbohydrate contains 4 calories, 1 g protein contains 4 calories and 1 g fat contains 9 calories. Food is generally composed of these three substances. Therefore, as long as we know the contents of these three substances in food, we can know how many calories or how much energy food contains.