In the international unit, energy should be expressed in joules. 1 calorie =4. 182 joules, then 1 kcal =4. 182 kj. This unit is sometimes used to represent the energy in food. Many times, people still use kilocalories to calculate the energy in food, because it is more convenient.

1 g starch or sugar contains 4 kilocalories; 1g fat contains 9 kcal, 1g protein contains 4 kcal. If you eat 10 g of fat, it will bring 90 kilocalories to your body. If you eat 50 grams of popcorn, you will increase the energy supply by about 170 kcal.

Energy intake per day:

Generally speaking, losing one kilogram every two weeks (1kg) is a relatively healthy and difficult way to rebound. It takes about 7700 calories to burn one kilogram (1kg) of fat. If you want to achieve the goal of reducing 0.5kg per week, you need to reduce about 500 calories per day. For the women just quoted, the daily intake should be: 2 147-500= 1647 calories.

It should be noted that even if the desire to lose weight is strong, it is not recommended that men consume less than 1600 calories a day and women less than 1200 calories.