Theory is not equal to practice. There are several factors that affect basal metabolic rate, such as food absorption rate and the proportion of oxygen consumption at rest, which are not easy to grasp and only have reference value and need not be calculated carefully.

The total consumption of a day during the fat-reducing period is basal metabolism plus exercise consumption, which should theoretically be greater than the total intake of a day. The difference between consumption and intake is the energy gap. According to this energy gap, the fat that can be reduced is estimated (for example, 9 calories per gram of fat). So in the last example, you should eat about 2200 calories a day. Theoretically, you can lose fat if you consume less than 2,500 calories, and 1.900 calories is an unscientific overeating.