The HCG diet uses a diet drops to help a dieter burn fat calories instead of food calories, with the goal being very rapid weight loss. In concert with the HCG diet drops, the dieter maintains a 500-calorie per day diet, forcing the body to burn fat instead of food calories.

The HCG diet has received criticism, with some suppliers who made exaggerated claims about the diet drops' effectiveness being shut down. The suppliers who remain defend the diet, saying that the FDA's complaint was with the marketing efforts of certain suppliers, not with the diet drops themselves.

The Very Low Calorie diet was developed by Dr. Simeon, the creator of the HCG diet drops. Designed to put the body into starvation mode, the Very Low Calorie diet plan forces the body to burn stored fat because food calories are not available. HCG diet materials stress the importance of sticking to this diet. Food is consumed only to ease the dieter's urges, not as the primary source of sustenance.

During breakfast, the diet plan recommends tea or coffee with one tablespoonful of milk. This is all the milk that is allowed during a 24-hour period. Sweeteners, especially artificial sweeteners like saccharine or herbs like stevia, may be added to the coffee or tea.

The diet plan recommends 100 raw grams of very lean protein at lunch. Meats such as lobster, chicken breast, white fish, shrimp, veal, or very lean beef qualify as acceptable sources of protein. Before cooking, any fat on the 100-gram portion should be cut away, and no additional fats should be added during cooking. Frying the protein in oil, even "healthy" oils such as olive oil, is not permitted. The meat should be prepared by grilling or boiling. Lunch can also include one kind of vegetable and fruit, such as a handful of strawberries, half a grapefruit, or one apple.

The same rules that apply to lunch also apply to dinner. The vegetable choice may include spinach, green salad, beet greens, tomato, onion, cabbage, asparagus, cucumber, chicory, asparagus, fennel, celery, red radishes, or chard.

As the HCG diet has become more popular, dieters have begun to share recipes for the 500-calorie diet, and a number of these are now available online. The diet drops come in a kit, which is sold by suppliers, and that kit also includes a detailed description of the Very Low Calorie diet.

As with any aggressive weight loss regimen, it is wise to consult a doctor before beginning the HCG diet. Long term health depends on weight control, and sometimes this means losing a considerable amount of excess weight. However, it is important to remember that dieting is about health, not only looking good. A doctor can help to guide aggressive dieting to protect health while also delivering a favorable cosmetic outcome.