• Fad diets are generally easy to understand and simple to follow (at least for a few days).
• Fad diets make great tabloid headlines and even better book titles.
• Since fad diets don't last, there's always room for a new one.

The problem with fad diets is that they are...fads. Following any diet for a time, even with exaggerated zeal, does not lead to long-term weight loss. And, when it comes to following today's fad diets, the results run the gamut from disappointing to dangerous. Let's take a look at some of the latest weight-loss fads.

Low-Carbohydrate Diets
These diets, described in a host of recent best-selling books, share a common theory: Carbohydrate-rich foods, especially those with sugar, wreak havoc on your physical and mental well-being. Eating these foods forces your body to make fat with abandon and leaves you moody, irritable and constantly hungry. The cure depends on whose fad you're following. Recommendations include avoiding carbohydrate-containing foods altogether by switching to protein-rich foods or fats, eating carbs at restricted times of the day or swearing off the most offending foods for life. The short-term health risks and negative side effects correspond with how extreme the fad diet is, ranging from marginal deficiencies of key vitamins and minerals to light-headedness and nausea. The bottom line is it's an excess of calories that causes you to gain weight. Incorporating complex carbohydrates provides many important vitamins and minerals, and when eaten in moderation, are part of a healthy diet.

Diet Pills and Supplements
Due to changes in the laws that govern the sale of dietary supplements, the number of pills, potions and herbal concoctions making weight-loss claims has skyrocketed. Recent estimates suggest that almost 3.5 million Americans are buying these products in an effort to control their weight, more than double the number in 1993. For the most part, the quality of the science behind these products is extremely weak, and the results have been inconsistent. In addition, side effects are largely unknown. What is known, however, is that combining dietary supplements with other pills (including over-the-counter medications) can be risky, and that at least one compound (known as ma huang, ephedrine and ephedra) has been linked with several deaths.

A Lifetime Plan
When it comes to weight loss, what your weight is at the end of a decade means a whole lot more than what it is at the end of a single day. In order to reap the many benefits of weight loss -from improved physical and mental health to having an entire wardrobe in a single size that you're happy withyou need to take the weight off and keep it off for an extended period of time. There is not a fad diet available that has shown it can make that happen. That's why the Institute of Medicine's expert panel has stated: "Because improvements in the quality of the diet and especially the amounts of food consumed are important to weight loss, as is modifying one's lifestyle to incorporate reasonable physical activity, any weight-loss program must attend to these two components, providing the participant with necessary information and, ideally, skills."