HCG (Human Chorionic Gondaotropin) is a hormone naturally produced in large quantity during pregnancy. HCG is used in infertility treatment for both men and women. Dr. ATW Simeons found that small regular doses of HCG caused the body to release abnormal fat when used in conjunction with a specific 500 calorie daily diet. This is detailed in Dr. Simeons manuscript Pounds and Inches: A New Approach to Obesity. This low calorie diet is only comfortable and advisable with HCG. Most participants are not hungry and have plenty of energy.