Requred Calories
 

It is about reducing calories so you can lose weight the safe and healthy way. If you are looking to lose weight start by finding out your Body's BMR this will give you your required daily calorie intake to start to lose weight the healthy way.

All you need to do is input several body factors including your energy level and it will meaure your body's caloric intake to start shedding the pounds.:D

It is a very good question and I am not expert but, I read somewhere and heard from doctors that a normal person needs 2000-2500 calories per day and it varies from body to body. But to become a slim and for loosing weight, a person should not take more than 2000 calories per day.