HCG is human chorionic gonadotropin, a hormone produced during pregnancy. Proponents of the HCG diet help to boosts metabolism and helps you lose large amounts of fat without you feeling hungry. The HCG diet plan recommends eating either 500 or 800 calories spread over two meals per day. The timing of these meals isn’t critical, but in general, calories are divided fairly equal between lunch and dinner. For breakfast, the diet recommends coffee or tea, which can be sweetened with stevia or saccharine. Since HCG also allows for one tablespoon of milk per day, many people elect to put it in their coffee at breakfast time.