This app allows to investigate how you can control body mass.
Umbrellapps user who created the web app: Andy15 Click and go to his profile.
1 kg of fat contains about 7700 kcals of nutritional energy. That means in order to burn 1kg of fat, you must have an energy deficit of 7700 kcals. Considering the average daily intake can be anywhere from 1800-2400 kcals, it takes some time to burn that fat. The energy deficit can come from a limited diet and from physical activity.