Reducing Carbohydrate is the most popular way the ones use to gain weight loss. This way helps to limit amount of calories received per day. Moreover, several studies show that metabolic advantage- weight loss is better wen ones consume isocaloric but lower carbohydrate- is more efficient way to increase weight loss. On the other hand, calorie is a calorie, it resist to thermodynamic law. This outline may describe how metabolic advantage can happen and what phenomenon that support it.