There is no specific standard for girls to lose weight in a day, because everyone's height and weight are different, so everyone's calorie intake is different. Generally, normal people need 2000 calories a day, while girls need less. It is ok to eat 1800- 1500 calories a day, but not too low. Too low can easily lead to malnutrition, which will have a serious impact on the body.
Obesity is mainly caused by intake exceeding consumption. The most important thing is to control the intake, don't eat high-calorie food, and combine exercise to achieve the purpose of losing weight.