All the ads promise miraculous results.... lose tons of weight really fast. In reality, most people should only strive to lose about a pound to two pounds per week. Knowing that eating 3500 more calories than you burn adds up to a pound, cutting 500 to 1000 calories a day along with adding exercise should help you reach this goal. You should, however, not eat below about 1200 calories per day. That is not healthy and can slow down your metabolism. Don't starve yourself. Eat healthier foods with high fiber, protein and water content. These are the things that help you feel satisfied. Good luck.