Similar in some ways to the Atkins Diet, the South Beach diet has been developed by Miami cardiologist Arthur Agatston. The program is largely based on the Glycemic Index (GI), which ranks foods (mainly carbohydrates) on a scale from 0 to 100, based on their immediate effect on blood glucose (sugar) levels after eating (glycemic response).

What do you eat on this plan?
The South Beach Diet has three phases. Phase one is a two-week, low-carbohydrate program where foods such as bread, pasta, potatoes, fruit and dairy products are eliminated.

Phase two involves the re-introduction of whole grains, fruits and dairy foods but processed carbohydrates, such as cookies, bagels, pasta and rice cakes, are to be avoided. Other foods to avoid include carrots, corn, bananas, raisins, pineapple, fruit juice and watermelon. Dieters are encouraged to stay with this phase until they reach their weight-loss goal.

Phase three involves similar foods to the second phase. Dieters who lapse are encouraged to go back to the first phase for a week or two to lose any weight they may have gained.

What's the verdict?
The GI is a scientifically recognized method of ranking carbohydrates in food. It is not, however, proven as a successful method of weight-loss. Counting calories and reducing fats, along with exercising regularly, is considered much more useful.

The menu plans in the South Beach Diet are roughly based on 1200 to 1400 calories per day, similar amounts recommended by experts for a weight loss of one to two pounds per week. However, in the menu plans, about 40-50 percent of the calories come from fat, which is higher than the 30 percent or less recommended by the American Heart Association.

As with the Atkins diet, eliminating or radically reducing one group of nutrients, such as carbohydrates, from the diet can have ongoing health consequences. Lack of carbohydrates can result in a lack of energy or fatigue. Skipping fruit or vegetables means that you are missing out on vitamins, minerals and antioxidants, all of which are essential for good health.

The Calorie King says: The GI is a useful tool for those watching their carbohydrate intake but you should still count calories to lose weight.

The Sugar Busters! plan is also based on the Glycemic Index (GI). This plan encourages dieters to cut out sugar from all sources, including the natural, unrefined and unprocessed sugars found in some fruits and vegetables, such as bananas, raisins, carrots and potatoes.

What do you eat on this plan?
The diet involves eating low-sugar fruits and vegetables, eggs, meats, low-fat diary foods and complex carbohydrates, such as whole-grain bread.

There is a list of foods to avoid which may be daunting to some people, especially if you enjoy bananas, carrots, sugary foods like donuts or desserts, and white bread.

What's the verdict?
While the program is low in fat on the whole, some of the menus suggested are very high in saturated fat. For example, one breakfast menu includes two eggs cooked in butter with sausage on the side.

Natural sugars found in fruit and vegetables are not bad for you. As with the Atkins and South Beach diets, skipping fruit or vegetables means that you are missing out on vitamins, minerals and antioxidants, all of which are essential for good health.

Avoiding high-sugar foods, such as cookies, cakes and candy, will have benefits for your health and will help you to reduce your overall calorie intake.

The Calorie King says: It's a good idea to reduce your sugar intake but not to cut out fresh fruits or vegetables.