When you take the HCG it triggers the hypothalamus (the gland in your brain that controls hunger and stored fats) to release your stored up abnormal fat cells and use them as calories. It helps you burn about 1500 – 4000 calories of stored abnormal fat every day. When you take the HCG in conjunction with the specific 500 calorie diet (following the approved food choices Dr. Simeons developed) you can burn up to 4500 calories per day. This is why you can lose so much so quickly. If you just eat a very low calorie diet without using the HCG, your body would go into “starvation mode”. It would start storing up the abnormal fat cells and burn the structural, normal fat and lean muscle that your body needs. It is crucial to use the HCG along with the very low calorie diet to get the best, longer lasting weight loss results you desire.