What are fad diets?

Fad diets are plans sold as the best and fastest approach to losing weight. Yet some of these diets involve eliminating foods that contain necessary nutrients that your body needs to maintain good health. Some diets claim particular hormones are to blame for weight gain, suggesting that food can change body chemistry. Often these diets aren’t well researched, or the research is faulty.

These are the kinds of diets that you often see endorsed by celebrities or promoted through media. Some hype particular foods like cabbage, foods that contain probiotics or raw foods. Or they may include high-fat, low-carbohydrate or high-protein diets. They eliminate important sources of nutrition, such as grains. Or they eliminate certain ingredients, such as lectins.

Some have you eliminate certain foods at specific times of the day. Others allow you certain foods, as long as you eat them along with certain other foods.

Although some diets may be recommended in special situations, many of these may lack major nutrients, such as dietary fiber and carbohydrates, as well as selected vitamins, minerals and protective phytochemicals. By not receiving the right amounts of these nutrients, you can develop serious health problems.

Of the food groups these diets do permit, the amounts are either well above or well below those recommended by major health organizations like the American Heart Association, American Diabetes Association, and the Academy of Nutrition and Dietetics — as well as the surgeon general and the U.S. Department of Agriculture.

All fad diets have one thing in common: They propose a temporary solution to what for many people is a lifelong problem. Once the diet is stopped, the lost weight is usually regained quickly. Fad diets don’t focus on lifestyle modification, which is necessary to keep the weight off, and these diets aren’t sustainable throughout life.

How do I spot a fad diet?

There isn’t a set approach to spotting a fad diet, but these general tips can help. Fad diets tend to have:

  • Recommendations that promise a quick fix.
  • Claims that sound too good to be true.
  • Simplistic conclusions drawn from a complex study.
  • Recommendations based on a single study.
  • Dramatic statements that are refuted by reputable scientific organizations.
  • Lists of "good" and "bad" foods.
  • Recommendations made to help sell a book or product.
  • Recommendations based on studies published without peer review.
  • Recommendations from studies that ignore differences among individuals or groups.
  • Elimination of one or more of the five food groups (fruits, vegetables, grains, protein foods, and dairy) or subgroups (grains, dairy, fruit).
  • Diets that have “testimonials.”

What is still the best method to lose weight and keep it off?

Exercise regularly and eat a variety of unprocessed or minimally processed foods with moderate portions.

Last reviewed by a Cleveland Clinic medical professional on 08/04/2020.


  • MedlinePlus. Nutrition. (https://medlineplus.gov/nutrition.html) Accessed 11/8/2021.
  • USDA Nutrition.gov. What You Should Know About Popular Diets. (https://www.nutrition.gov/topics/healthy-living-and-weight/what-you-should-know-about-popular-diets) Accessed 11/8/2021.
  • Academy of Nutrition and Dietetics. Staying Away From Fad Diets. (http://www.eatright.org/resource/health/weight-loss/fad-diets/staying-away-from-fad-diets) Accessed 11/8/2021.
  • American Academy of Family Physicians. Nutrition for Weight Loss: What You Need to Know About Fad Diets. (https://familydoctor.org/nutrition-weight-loss-need-know-fad-diets/) Accessed 11/8/2021.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy