This actually can wind up doing more harm than good. If you don't give your body enough calories it can go into Essentially, what this means is that your body begins to think you are starving so it slows down your metabolism to try to conserve energy. It doesn't matter if your brain knows that you can get more food anytime you want your body just reacts to what it senses which is that you aren't getting enough calories. Rather than going on a very low calorie diet focus instead on eating small, healthy, balanced meals times per day that give your body the nutrition and energy that it needs. Breaking down your eating into small meals and giving your body the proper nutrition will help to boost your metabolism and make burning fat a whole lot easier.