You will not burn the calories you consume, because your body doesn’t want to starve. In order to remain healthy, you should not eat less than 1200 calories in a day. Less than this and you could jeopardize your health.
The second reason fad diets aren’t diets that work is loss of muscle tone. Once your body thinks it is starving, it will start to use your muscles as its food source. By burning muscle to give you enough energy to get through a day you won’t be losing any fat. You may see a reduction in your weight on a scale, but in reality it is not a true representation. Once you increase the amount of calories you will see your weight climbing again.diets that work