There is no such thing as “how much weight will actually be lost if you lose 1kg of fat”, because if you lose one kilogram of fat, your weight may go down, or it may go up or remain the same. Fat is mainly found in the subcutaneous tissue of the human body, which can supply abundant heat energy to the body. Losing fat is achieved through dietary control and exercise. Exercise may also result in an increase in muscle mass, which is much heavier than fat, and the same volume of fat will weigh more compared to muscle. If 1kg of fat is lost and there is no increase in muscle mass in the body, then weight loss will generally occur. If you lose 1kg of fat and your muscle mass increases with physical activity, you may gain weight, but your body will look firmer and leaner. If you lose 1kg of fat and your muscle mass increases only a little, then your weight may remain the same. People who need to lose weight or fat should follow a scientific and rational approach.