A fad diet is any diet that becomes popular for a short period of time due to stories of success from a relatively small number of people.  They are advertised as quick ways to lose weight.  Most of these diets require a low intake of specific foods or nutrients for a certain period of time.  Some of them have various stages to reintroduce the limited food or nutrient.  Here are some examples of fad diets and why they don’t work:

The South Beach Diet – While the South Beach diet does teach some balancing of intake and does include information about glycemic index, it overly limits carbohydrates and involves changing intake over a period of weeks or months.  Low carbohydrate diets deprive the body of energy it needs and often lead to muscle wasting instead of fat loss.  This also makes the South Beach diet essentially a high-protein diet since it is low in carbs but does not promote raising dietary fat intake.  High-protein diets can be beneficial for people with certain conditions, but they are usually not recommended for the general population.  Because the eating plan changes every week or two, following the diet is difficult.  Just as someone following the diet learns how to eat according to the plan, it changes.  It can also make it difficult for the body to regulate blood sugars since the level of carbohydrate intake is changing.  Using the glycemic index can be very helpful, especially for people with diabetes, because it measures how fast and how much a certain food causes a rise in blood sugar.  However, it is generally not necessary for the average person to worry about glycemic index or to limit high glycemic index foods since their body will adjust to rising blood sugars appropriately.

The Atkins Diet – This is actually similar to South Beach but recommends a higher fat intake as well as a higher protein intake with the low carb approach.  So in addition to the reasons mentioned above, Atkins can possibly lead to adverse effects like high triglycerides or cholesterol.

The Special K Diet – Eating a bowl of cereal for breakfast and one for lunch, along with a “sensible” dinner, does in fact often lead to successful weight loss.  The cereal actually provides a decent balance of nutrients, vitamins, and minerals, but it does not benefit the body the same way as whole foods would and can encourage overly limiting calorie intake.  Balancing the diet with adequate fruit and vegetable intake is a better way to decrease unhealthy calories and help aid weight loss.  There have been several studies that show many different benefits to consuming whole foods as opposed to limiting the diet to too much of one food or supplement.

Any “Cleanse” – Cleanses come with a time limit anywhere from one day to two weeks or more and involve limiting the diet to only a few foods or fluids to “cleanse” the system.  What these diets actually do is deprive the body of nutrition.  Weight loss may be observed while on the cleanse because some of these cause fluid losses, but the weight is usually regained once a regular diet is resumed.

There are several more diets out there and more being popularized all the time.  The best way to lose weight is to avoid overeating any one food group and balance intake with appropriate portions.  Be sure to include at least three food groups at every meal.  Then follow the age-old rule for good nutrition: Eat when you’re hungry and stop when you’re full!