Fad Diets


Fad diets are diets that promise quick weight loss results. These diets are generally not sustainable due to unrealistic expectations and may even be harmful.


Fad diets have been around for centuries. In 1820, Lord Byron touted a diet that has sometimes made a comeback as popular aid to weight loss. His vinegar and water diet mixed apple cider vinegar with water. The Grapefruit diet, also known as the Hollywood diet, began in the 1930s. The 1950s brought the cabbage soup Diet, and the 1970s introduced the cookie diet, featuring cookies with amino acids; Slim Fast shakes; the Scarsdale diet; and Dexatrim diet pills. During the 1990s, the Atkins, Zone, and Macrobiotic diets made their appearance. These were followed in the 2000s by the South Beach, Master Cleanse (lemon juice, cayenne pepper, and maple syrup in hot water), and HCG (fertility pill combined with extremely low calorie intake) diets.


Despite the popularity of dieting, the prevalence of overweight and obese individuals has increased steadily since the 1970s. In 2013–2014, approximately 71% of adults living in the United States who were aged 20 years and older were overweight or obese. Between 9%–21% of children under the age of 18 were obese, with prevalence increasing with age.


Fad diets seem relatively easy to implement and claim remarkable improvements in how their followers will look or feel. Unfortunately, the one thing most fad diets have in common is that they seldom promote safe and/or long-term weight loss efforts. More importantly, fad diets that do not incorporate healthful eating and exercise fall short in incorporating the needed behavior changes for long-term weight maintenance. It is realistic to state that most diets work in the short term, but reports show that after five years, less than 10% of people maintain a 5% loss from their initial body weight. With so many conflicting diets available, it is not surprising that many are confused when it comes to information about how to lose weight safely and for the long term.

Types of fad diets

Fad diets take many forms. Over the years, fad diets have circulated around either the promotion of food in specific combinations or the elimination or increased consumption of certain macro- and/or micronutrients for the purpose of weight loss. Some of the most popular types of fad diets include:

Representation of popular fad diets.

Representation of popular fad diets.
(Bon Appetit/Alamy Stock Photo)

If fad diets resulted in long-term maintenance of weight loss efforts, the problem of obesity would likely have been solved long ago.

Some fad diets have been popular for many years (e.g., Atkins Diet Revolution). Books appear as new, revised editions and continue to sell millions of copies. Rarely is there anything new or revised about the diets; they simply appeal to a new generation of overweight, frustrated dieters.

Recognizing fad diets

The American Heart Association provides some tips that can be used to recognize a fad diet. First, does the diet contain magic or miracle foods or proprietary ingredients? There are no super foods or magic ingredients that can undo the long-term effects of overeating and lack of activity. Next, beware of fad diets that claim rapid weight loss (e.g., “lose ten pounds this weekend!”). Though appealing, weight loss occurring this quickly is due to loss of fluid, not fat. Studies show that gradual weight loss increases a person's success at keeping weight off permanently. Sound weight loss plans aim for losing no more than one to two pounds per week.

Another sign of a fad diet is losing weight without exercise. Studies consistently show that an important variable that predicts long-term success in weight loss and maintenance (not gaining back the weight that was lost) is physical activity. Simple activities, such as walking or riding a bike, should be incorporated into daily life. Also, beware of the promotion of bizarre quantities of foods or the elimination of other types of foods (e.g., cabbage soup for breakfast, lunch, and dinner; avoiding dairy foods; or eliminating carbohydrates). Forbidding certain foods or entire food groups, in addition to being unhealthy, may increase the likelihood that one will cheat, binge, or just give up on the diet. Finally, a rigid menu or rigid schedule of eating is a good sign that one should avoid the diet. Limiting food choices and adhering to specific eating times is a daunting task. Rather, one should look for a plan that can be followed not for a week or a month, but for an entire lifetime.

Not all commercially advertised diets are fad diets. The Weight Watchers program, for example, is a diet and lifestyle program that follows sound medical and scientific advice.


Knowledgeable practitioners do not recommend fad diets, because such diets do not work in the long term. Even though they might work initially, there is little value in losing weight if the weight is going to be regained after the diet ends (sometimes called the yo-yo effect). With repeated dieting, weight loss becomes more difficult and results in frustration, feelings of failure, and loss of self-esteem and may be harmful to health.

From a nutritional standpoint, many fad diets lack important nutrients. For example, high-fat, low-carbohydrate diets (such as the Atkins diet) are low in vitamin A, vitamin B6, vitamin E, thiamin, folate, calcium, magnesium, iron, zinc, potassium, and dietary fiber. They also require the dieter to take dietary supplements. When individuals are allowed to choose foods from all food groups and control their portion size, and are encouraged to increase their physical activity, the diet is likely to be nutritionally adequate and sustainable.


The underlying reason that diets, including fad diets, work is that they result in decreased caloric intake. When energy intake is less than energy expenditure, people lose weight. Fad diets that lead to decreased caloric intake, whether by eliminating certain macronutrients, eating only a restricted amount of foods, or decreasing overall energy intake in various other ways, will result in weight loss. If a person followed such a diet long term, he or she would keep the weight off, although general health would likely be impaired because these diets are not nutritionally balanced. Of course, few people want to live on cabbage soup or eliminate carbohydrates forever, so most people break the diet and gain back the weight they lost— and sometimes even more.

Fad diets are popular because they promise quick results, but the most effective and safe way to lose weight is by increasing physical activity over time and reducing caloric intake by choosing foods that are nutrient dense, such as fruits, vegetables, whole grains, lean proteins, and low- or nonfat dairy foods. Fad diets counter this healthy eating pattern as well as the information provided by science-based governmental and nongovernmental organizations.


Major concerns have been raised over the weight cycling of people who follow fad diets on and off over a period of years. Rapid weight loss and fluctuations of weight gain/loss have been shown in research studies to increase risk factors for major health problems, such as gallbladder problems, Type 2 diabetes, and cardiovascular disease, which increase the risk of mortality. Further, some experts suspect that weight cycling may lower the metabolic rate, increase fat-to-lean ratio and waist-hip ratio, increase the appetite, and decrease a person's ability to lose weight in future attempts. There is also concern over the mental effects this may have on self-esteem and the relationship a person has with his or her own body. Over time, people who have not had long-term success in their weight loss efforts may show more signs of depression.

Dietary supplement—
A product, such as a vitamin, mineral, herb, amino acid, or enzyme, that is intended to be consumed in addition to an individual's diet with the expectation that it will improve health.
An inorganic substance found in the earth that is necessary in small quantities for the body to maintain health (e.g., zinc, copper, iron).
Type 2 diabetes—
Sometime called adult-onset diabetes, this disease prevents the body from properly using glucose (sugar).
Very low-calorie diet—
A diet of 800 calories or fewer per day.
A nutrient that the body needs in small amounts to remain healthy but that the body cannot manufacture for itself and must acquire through diet.

Parental concerns

For some children, the doctor may recommend weight loss or weight maintenance. A child or adolescent should not attempt a weight loss diet, especially a fad diet to lose weight. Children who need to lose weight should do so under the supervision of a doctor, which may include a visit with a dietitian who can explain how to reduce calories safely, while still getting all the necessary nutrients for growth, puberty, and weight loss or weight maintenance.

See also Abs diet ; Adolescent nutrition ; Alkaline diet ; Atkins diet ; Beverly Hills diet ; Blood type diet ; Cabbage soup diet ; Calcium ; Calories ; Cambridge diet ; Chicken soup diet ; Detoxification diets ; Dietwatch ; Dr. Feingold diet ; Dr. Phil's diet ; Fit for Life diet ; Grapefruit diet ; Hollywood diet ; Juice fasting ; Low-sugar diets ; Mayo Clinic diet (fad diet) ; Obesity ; SlimFast ; 3-day diet ; Vitamin A ; Vitamin B6 ; Vitamin E ; Weight cycling ; Weight Watchers .



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Heart Insight. “Dont Be Had by Fat Diets.” American Heart Association. http://heartinsight.heart.org/Spring-2017/Dont-Be-Had-By-Diet-Fads (accessed May 16, 2018).

Matus, Mizpah. “Fad Diets.” Free Dieting. https://www.freedieting.com/fad-diets (accessed May 16, 2018).

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Academy of Nutrition and Dietetics, 120 S. Riverside Plaza, Ste. 2190, Chicago, IL, 60606-6995, (312) 899-0040, (800) 877-1600, amacmunn@eatright.org, http://www.eatright.org .

American Heart Association, 7272 Greenville Ave., Dallas, TX, 75231, (888) 242-8883, help@onlineaha.org, https://www.onlineaha.org .

American Society for Nutrition, 9211 Corporate Blvd., Ste. 300, Rockville, MD, 20850, (240) 428-3650, Fax: (240) 404-6797, http://www.nutrition.org .

Obesity Society, 1110 Bonifant St., Ste. 500, Silver Spring, MD, 20910, (301) 563-6526, Fax: (301) 563-6595, http://www.obesity.org ., http://www.obesity.org/resourcesfor/consumer.htm .

Overeaters Anonymous, 6075 Zenith Court NE, Rio Rancho, NM, 87174-4020, (505) 891-2664, Fax: (505) 891-4320, https://oa.org .

Weight-Control Information Network, National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center, 9000 Rockville Pike, Bethesda, MD, 20892, (800) 860-8747, healthinfo@niddk.nih.gov, https://www.niddk.nih.gov/health-information/communication-programs/win .

Marjorie R. Freedman
Revised by Anne P. Nugent, PhD

  This information is not a tool for self-diagnosis or a substitute for professional care.