The feast-and-famine diet is only the most recent trendy diet to come onto our radar. In the past, the ABC News Medical Unit rounded up some of the most popular diets to date and subjected them to the scrutiny of nutrition experts Joanne Ikeda, cooperative extension nutrition education specialist and lecturer in the Nutritional Sciences Department at University of California, Berkeley; Dr. David Katz, co-founder and director of the Yale Prevention Research Center; and Keith-Thomas Ayoob, director of the nutrition clinic at the Albert Einstein College of Medicine.
The following pages feature each of these diets, as well as whether you can count on them to help you achieve a healthier weight.
What It Is: The 4 Day Diet is the brainchild of Dr. Ian Smith, author and diet consultant for VH1's "Celebrity Fit Club," who found that people were not complying with their diet plans because they suffered from what he called "food boredom."
"People get tired of eating the same thing over and over again," Smith said. "This is a way to move the food around so people are eating good food and don't get tired of eating it because they know new foods are coming. ... Even if they were in a tough phase, they knew it would only last four days. From a psychological standpoint, that's a great boost."
Smith's plan is based on seven mix-and-match four-day-long modules that consist of a defined food group or plan. For example, the Induction module is meant to detoxify and cleanse the system, while the Protein Stretch module incorporates foods such as eggs, lean meat and vegetables; the Smooth module allows people to indulge in forbidden favorites such as pizza. Together with exercise, Smith said his modules keep the body from becoming accustomed to one diet plan.
Expert Verdict: Katz: "Obviously there is no science to back this up. The ultimate goal of 'dieting' should be to establish a stable, healthful dietary pattern; I see no hope whatsoever of that here. So this is all about, and only about, short-term weight loss -- which just about any diet can provide. ... What is the right answer? Learn to choose wholesome foods; learn to use them in wholesome meals; and make a lifelong commitment to healthful eating and regular activity that includes the other members of your household. That's the truth."
Ayoob: "This diet has some nice aspects to it, but balance isn't one of them. ... It's different each day, it's not boring. It encourages you to keep a food diary. It allows you an occasional indulgence so you don't feel deprived. Lots of fiber, fruits and veggies. I especially like that it includes beans -- a terrific food. [But] some dieters will find that they need at least some consistency. Lots of different calorie intakes over the four days; some are really low, some not."
Ikeda: "Like most diets, [this one] can result in weight loss. ... My big criticism of this diet is it does not teach people how to eat a healthy, well balanced, nutrient-dense diet that they can keep eating for the rest of their life. ... And I don't care how well one eats, if a person is not physically active, they are not going to be healthy."