This is also called the 'yo-yo effect'. That is why it is better, if you want to lose weight permanently, to allocate a longer period for this. Although losing weight is slower, it does not disrupt your metabolism, which means that you will not gain weight very quickly after the diet. If you want to lose weight it is wise to focus on your fat percentage and not on the scales. The macronutrients of fat, protein and carbohydrates are essential for our body.