Fad diets are diets designed to be followed for only a short period of time. The term has also come to mean any diet that explodes into national or international fame, only to plummet into obscurity. Examples include the grapefruit diet, the South Beach diet, and Jenny Craig.

Fad diets are sometimes known as food fad-ism. Any time one particular food suddenly becomes a superstar, that's a food fad. These generally have some common elements, including:

• The food is attributed with miraculous powers.

• Many other foods are completely eliminated from the diet, because they are thought to have negative properties.

As an example of these elements of fad diets in the diet, take the Atkins diet. In Atkins carbohydrates must be avoided because of their negative characteristics. Carbohydrates take on both of the common elements in that removing carbohydrates from the diet creates a near magical metabolic state in which fat is burned at an incredible rate. This diet had a number of short periods of extreme carbohydrate avoidance, followed by long periods of sustainable low carbohydrate eating. However, many people are able to continue the Atkins diet for years.

As with many fad diets Atkins rose quickly and fell just as quickly. For a number of years the Atkins diet was everywhere, and everyone seemed to be following it . Entertainment magazines were full of movie stars and music stars and sports stars who claimed amazing weight loss and fitness all due to the Atkins diet. Although still around today, the diet is far from as popular as it was at its height.

Fad diets can be unhealthy. The Subway diet made popular in television commercials wasn't exempt. It was based on the legend of Jared, a young man who'd lost nearly 250 pounds in only a year by eating Subway sandwiches, baked chips, and diet soda. In reality Jared cut his caloric intake from over 10,000 calories a day to only 900. Such an extreme level of caloric intake cuts and rapid weight loss is unhealthy. Even so in moderation the Subway diet can work, particularly when combined with exercise -- Jared walked 6 miles a day.

Beware of fad diets. A healthy combination of reasonable diet and exercise in the long-term can help you lose weight and maintain a healthy lifestyle.

Even though they are popular, Fad Diet Plans are stereotyped in a negative light. If they are used by so many to lose weight can they really be all that bad?