It is not true that one size fits all. We are all individuals and what is right for one person may definitely be wrong for another.

These following diets are recommended by nutrition experts and most importantly, by the people that have successfully used them.

Cabbage Soup Diet

The Soup Diet, as it is commonly referred to, contains negligible calories and is based on a fat burning process. This diet consist on a combination of foods that almost force you to starve everyday although you are allowed to consume all the water and cabbage soup you want and a very restricted set of other foods.

The cabbage soup diet has a 7 days diet plan losing 10 to 15 pounds. This plan includes a variety of low calorie vegetables like cabbage, onions, and tomatoes, flavored with bouillon, onion soup mix, and tomato juice.
Each day has specific foods including potatoes, fruit juice, many vegetables, and on a single day, beef.

In day one you can eat only fruit, any fruit you want except banana and as much soup as you like. Drink only unsweetened tea, black coffee, cranberry juice, and water.
For day two stay away from dry beans, peas, and sweet corn but you can eat fresh, raw, or cooked vegetables. For dinner eat a big baked potato with butter for your satisfaction. Of course as much soup as you like, but no fruit.

In day three combine days one and two but no baked potato.
Day four is supposed to reword your desire for sweets, so eat eight bananas and drink as many glasses of skim milk as you would like. Dont forget your soup!

In day five you may have 300 to 500g of beef (10 to 20 ounces) and up to six fresh tomatoes. If you want you can change the beef with boiled fish or baked chicken. It is recommended to drink at least 6 to 8 glasses of water to wash the uric acid from your body. Eat your soup at least once this day.

In day six eat beef and vegetables and two or three steaks with fresh vegetables or salad but no baked potato. Eat your soup at least once today.

This final day you can eat all you want of brown rice, unsweetened fruit juices, and vegetables, of course, eat at least your soup once and no bread, alcohol, or carbonated beverages, not even diet soda.

Medifast is a weight loss plan using meal replacements AND real food. The program has been prescribed by doctors especially for obese people.
Medifast comes with a 5 and 1 plan and is made up of 5 meal replacements per day - generally shakes, but also bars, soups, oatmeal, and puddings.

One meal per day contains a small portion of lean meat, and up to 2 cups of salad or vegetables. The eating periods are at every 2 to 3 hours and you must drink a minimum of 64oz of water per day.
The 5 and 1 plan is a vast improvement on some of their previous programs and although it is not a very low calorie diet, you can loss 2 to 5 pounds per week.

Another very popular diet is called 3 Hour Diet and is a book written by fitness author Jorge Cruise The 3 Hour Diet How Low-Carb Diets Make You Fat and Timing Makes You Thin
The basic premise of the 3 Hour Diet is to eat a meal every 3 hours. The main idea is to increase metabolism, and to help maintain consistent energy levels throughout the day.

Jorge Cruise recommends exercise, 8 minutes every day!
Every day meals are based on a source of lean protein, carbs, and healthy fats and the various fast food and frozen food. The calorie amounts of the suggested daily meals amount to 1450 calories per day. The 3 Hour Diet is heavy on processed food, which can be of questionable nutritional value.

What is a GI diet?

Foods with a high GI value cause a rapid rise in blood sugar. This can often leave you feeling hungry within a short time, and will often result in eating a snack. If this pattern is repeated often, you will gain weight by constantly overeating.

Diets based on low GI value encourage you to avoid eating foods with a high GI value and it helps to prevent swings in blood sugar, helping you feel fuller longer. Most GI diets recommend reducing fat and especially saturated fats.

The Glycemic Impact Diet is an excellent diet because it takes the best from other diets like South Beach and the Zone and combines them with easy to follow advice.