Can Fad Diets Work?

Many dieters are still trying to find the magic bullet to weight loss. WebMD gets the skinny from experts on the latest quick-fix diets.

Medically Reviewed by Louise Chang, MD
6 min read

When singer Beyoncé Knowles needed to lose 22 pounds in a hurry for her role in the film Dreamgirls, she went on a crash diet that consisted of drinking a mixture of water, cayenne pepper, and maple syrup as a substitute for regular meals. She lost the weight, and in the process sparked a run on maple syrup as news and photos of her newly svelte figure spread. But even Beyoncé has been quick to tell interviewers, "I would not recommend it if someone wasn't doing a movie, because there are other ways to lose weight."

Beyoncé's own caution to dieters probably comes as good news to nutritionists who don't think much of her quick-fix weight loss plan. "This diet is void of essential nutrients and probably doesn't promote healthful eating and lifestyle habits that would sustain any weight that is lost," says Jenna Anding, PhD, RD, LD, associate department head, department of nutrition and food science, Texas A&M University. "Also, losing 20 pounds in two weeks is not healthy; nutrition experts recommend a weekly weight loss of no more than 2 pounds per week."

The "syrup diet" is just one of the many diet plans (albeit one of the more extreme) to capture our weight-crazed fancy over the years. From Atkins to South Beach to the Zone to the Blood Type Diet -- to name just a few -- many of us are always on the lookout for the "magic bullet" that will help us shed pounds quickly, and more or less effortlessly.

Why, despite the advice of most nutrition experts, are we fascinated by the myriad diet plans crowding bookstore shelves? "Most individuals want cutting-edge solutions for weight loss, and fad diets offer, at least on the surface, 'new' ways to beat the boring mathematical reality of long-term weight loss," explains Robin Steagall, RD, nutrition communications manager for the Calorie Control Council.

"All diets work on the principle of cutting calories [cutting 500 calories a day can result in a 1-pound weight loss in a week]," Steagall adds, "but every new diet has some unique twist to accomplish this mission."

Among the newest, for example, is The Fast-Food Diet, co-authored by Stephen Sinatra, MD, and Jim Punkre, which capitalizes on the American love affair with, yes, fast food. While the diet doesn't promote fast food per se, it acknowledges that many of us (on any given day, the authors say, 25% of our population) visit fast-food restaurants because they're convenient and affordable.

So, they suggest, if you're there already, make healthy choices that can lead to weight loss. Some tips: Choose the smallest drink size, or better yet, switch from soda to club soda or water; order from the children's menu; or eat a baked potato, not fries.

Another currently popular program, the Maker's Diet, created by Jordan S. Rubin, is based on the theory of a "biblically correct diet and lifestyle," including modest portions of whole foods from sources consumed in as close to a natural (unrefined and unprocessed) state as possible. Rubin's plan also focuses on emotional and spiritual health. His diet's seven keys are: eat to live; supplement diet with whole foods, living nutrients, and superfoods; practice advanced hygiene; condition your body with exercise and body therapies; reduce toxins in your environment; avoid deadly emotions; and live a life of prayer and purpose.

Clinical dietitian Janet Basom of the Joe Arrington Cancer Center (JACC) in Lubbock, Texas, says that just because a diet plan -- more specifically, this particular diet plan -- is on the best-seller list, doesn't mean that it doesn't work or that it's not sensible.

"Through both my professional and personal experience, this plan is in tune with what I believe to be true," says Basom.

"This isn't a 'far-out' diet," Basom adds. "The goal of the program is to help people make permanent lifestyle choices, not necessarily to lose weight. It's more about teaching people to make the best selections, not only in what they eat, but in how they live."

Basom has been so encouraged by the results of the Maker's Diet that she has received a grant to conduct a research trial on the program among the 100-plus employees at JACC.

Not every popular, new diet can be classified as a "fad" diet, says Basom, which she defines as one that is more of a "quick fix" that is not going to lead to improved health, and that can't be pursued on a long-term basis.

There are several ways to recognize a fad diet, suggests Steagall. A fad diet:

  • Doesn't include the variety of foods necessary for good health and/or doesn't teach good eating habits.
  • Claims you can "trick" the body's metabolism into wasting calories or energy.
  • Makes dramatic claims for fast and easy weight loss.

"In reality, all of the glitz and glamour approaches will probably not be effective for safe and long-term weight loss if they don't incorporate a balanced, healthy diet and increased physical activity," says Steagall.

One popular diet that vigorously promotes exercise is the Fat Smash Diet, seen by TV viewers on VH1's Celebrity Fit Club. Host -- and author of the diet -- Ian Smith, MD, has made exercise an important focus of the program, with a "prescription" for 30 minutes of exercise, five days a week, in the initial stage of the program, and an increase in activity in each of the remaining three stages.

Smith has said that the 90-day program is designed to change our approach to eating and exercising by making lifestyle changes. You first "detoxify" by eating mainly fruits and vegetables for nine days, with no meat, bread, cheese, coffee, or alcohol allowed. During the "foundation" phase, which lasts three weeks, more foods appear on the permissible list and exercise is kicked up 10% to 15% above phase one. The four-week "construction" phase allows for an occasional treat, and exercise jumps 25% over phase two. Once dieters reach the lifetime "temple" phase, Smith claims they will have constructed a routine of good habits that will last a lifetime.

While there may be some credibility to the "jump start" that dieters can get from an initial quick-loss phase of a weight loss regimen, most successful diet plans are designed for gradual weight loss and modified behavior, says Robert Eckel, MD, president of the American Heart Association (AHA).

"If you're healthy, a quick, short-term weight loss -- perhaps motivated by a special event, like a wedding or reunion -- is not likely to be harmful," says Eckel. "In the long run, however, most such plans are fairly extreme and hard to adhere to."

Recognizing this, the AHA has claimed its own bookshelf space with the American Heart Association No-Fad Diet: A Personal Plan for Healthy Weight Loss. The program promotes healthy eating choices, increased physical activity, tips for maintaining your success, and advice on creating a healthy eating environment for the entire family. Through questionnaires that help users identify what kind of dieter they are, the plan offers three different options that make it "user friendly," says Eckel.

Healthy people can probably begin most weight loss programs on their own, Eckel advises. If you have any existing illness, however, he cautions that you see your doctor first. That advice is reiterated by the American Diabetes Association (ADA), which strongly recommends that people with diabetes avoid fad diets, such as those that promote extreme low-carbohydrate or high-protein intake.

In the September issue of Diabetes Care, Ann Albright, PhD, RD, writes, "There is no evidence that these diets are successful at helping people keep weight off once they lose it, and there are ample concerns about the fiber, vitamins, and minerals people give up when they severely restrict their diet, say, by sharply limiting carbohydrate intake.

"Fad diets come and go," continues Albright, who is ADA president-elect for Health Care and Education. "We want people to be provided with sound nutrition advice that will help them in making choices for maintaining good health for the long term."

"While fad diets may take the weight off, they don't teach you how to keep it off," emphasizes Steagall. "Remember, you're learning a way to live, not just a way to diet.

"To keep the weight off, you must stay motivated," Steagall adds. "Successful weight control depends upon you -- not upon any particular product or program, no matter who is promoting it or how glamorous it appears on the surface. 'All that glitters is not gold.'"