Invented in the 1970s, the Scarsdale Medical Diet is a stringent 14 day, low-calorie diet that leaves no room for interpretation. It is an all-or-nothing program to be followed exactly as written, down to the very last bite. Extremely restrictive in calories, the plan is based on a ratio of 43 percent protein, 22.5 percent fat and 34.5 percent carbs. Followers have dropped up to 20 pounds in two weeks under the guidelines of the Scarsdale Diet, although the average person loses between 7 to 15 pounds consuming between 800 to 1,000 calories a day.

There is a set of rules that must be followed. Eat only what is on the meal plan. Cut out all alcoholic beverages. Snacking is off limits unless it is carrots, celery and low-sodium vegetable broth. Permitted beverages are things like plain coffee, tea, club soda, diet soda and sugar-free drinks and water. Salads should only be consumed with lemon and vinegar or the Scarsdale-approved dressings. Vegetables must be eaten without butter, margarine or other fats. Consume only lean meats. Do not have any additions or substitutions. Only stay on the diet for two weeks at a time, alternating between the main plan and the Keep-Trim eating program, a maintenance period to reset the body's metabolism.

Breakfast is 1/2 grapefruit, a slice of protein bread and plain coffee or tea - every day. Lunch varies from cold cuts, tomatoes and coffee to tuna fish salad with lemon and vinegar dressing, grapefruit and coffee. Choices for dinner range from sliced roast lamb, a salad of lettuce, cucumbers, tomatoes, cucumbers and celery and coffee or fish, a combination salad, one slice of protein bread and coffee.

There are many red flags with the Scarsdale Diet. For starters, it is low in calories and high in protein. The program also encourages the use of artificial sweeteners and herbal appetite suppressants. Critics also point out that if you do not get enough water when following the diet, there is a risk of kidney damage.