According to the Centers for Disease Control and Prevention, nearly half of American adults try to lose weight year-round. Some take a balanced approach, changing lifestyle habits and improving their diet to achieve their goal in a slow and steady manner. Others, however, try a so-called fad diet, or a popular diet plan designed to help you lose weight quickly, a study shows.
The hallmark of a fad diet is restriction, says Melissa Rifkin, RD, based in Mount Kisco, New York. To achieve rapid weight loss – something most popular diets claim – you generally need to eliminate certain foods. “Fad diets are typically extremely restrictive, causing followers to miss out on certain food groups or nutrients, which can deplete our bodies,” she explains. Unfortunately, many people tend to give up on these diets quickly when they start craving the foods on the “don’t eat” list, a natural response to inflexible dietary rules.
Fad diets come and go, but some have stood the test of time, reinvented themselves or become so popular that they are easy to remember. Here’s a look at 10 of the most famous fad diets of all time – and whether they’re worth following.
1. Atkins diet
Atkins is all about eating low-carb, and the modern Atkins program allows you to choose your carb goals, from 20 grams (which mimics the ketogenic diet), 40 grams or 100 grams per day. Stricter carbohydrate goals ensure faster weight loss. Although it’s a famous diet, many people just don’t find it sustainable, says Leah Reitmayer, RD, a sports dietitian in Fayetteville, North Carolina. “Carbohydrates are your main source of energy. I don’t recommend low-carb eating because your body needs this macronutrient. If you’re trying to diet to be healthy, why would you take out the most important nutrients your body needs to be healthy?” she says.
2. Zone diet
The Zone Diet, made popular by Jennifer Aniston, involves eating 40 percent carbohydrates, 30 percent protein and 30 percent fat. “This diet has some merit because it is based on whole foods and emphasizes protein and omega-3 fatty acids for an anti-inflammatory effect,” says Alyssa Smolen, RDN, based in Essex, New Jersey. Although it is balanced, the diet still lists certain nutritious foods that are banned, such as bananas, raisins, potatoes and corn, and directs you to eat less than one serving of grains and starches per day – rules that can make it harder to maintain this diet in the long term.
3. Keto diet
The keto diet, a high-fat, very low-carb diet, was originally developed as a medical diet to treat epilepsy in the 1920s, according to research. It had to wait 100 years before it reached its peak popularity among the general public: In 2020, the keto diet was the most Googled diet in the United States, according to one review. One downside is that people eat a lot of meat and cheese on this diet, which can contribute to excessive intake of saturated fat, a type of fat that can increase the risk of heart disease, Smolen says. Moreover, consumption of fruits and vegetables may be low, something that is detrimental to health, she adds. If you’re going to do keto, Smolen recommends doing so under the guidance of a medical team or registered dietitian so you can be sure you’re building a nutritious diet, following keto correctly, and monitoring your health.
4. Grapefruit diet
It would be just as easy to replace grapefruit with one of the single-food diets of recent years, such as cabbage soup, boiled egg or bone broth. All of these foods are good for you, but not as the sole focus of your entire diet. “No food contains everything you need. That’s why dietitians recommend eating a variety of fruits, vegetables, proteins and whole grains,” says Smolen. Although you may lose weight on a grapefruit diet, that’s because you eat fewer than 1,000 calories per day due to the strict food restrictions. In general, dietitians recommend skipping these types of diets.
5. Paleo diet
Paleo, short for Paleolithic, is a diet consisting of the food of a traditional hunter-gatherer. People who follow a paleo diet consume half their calories from lean animal foods, as well as from eggs, fruits, non-starchy vegetables, unsaturated fats, some alcohol and water. There are major health claims associated with the paleo diet, including as a cure for heart disease, diabetes and cancer, according to a review. But one thing that’s not being tracked is that whole grains — a food group linked to lowering the risk of these diseases — are excluded from the paleo diet, notes the American Academy of Nutrition and Dietetics. Another major drawback is that following a diet that excludes so many foods can lead to unhealthy obsessive thoughts about your diet, says Smolen.
6. Gluten-free diet
For many people with celiac disease or an allergy to gluten (the protein found in wheat, barley and rye), avoiding foods containing gluten isn’t a fad diet — it’s a necessity. But gluten-free became a fad diet when people began avoiding gluten for lack of medical necessity, thanks in part to celebrity advocates like Gwyneth Paltrow, as E! News reported. Ten years ago, most adults said gluten-free foods were healthier, and more than a quarter bought them to lose weight, surveys from the time show. But there is simply no evidence that gluten-free diets promote weight loss in general, according to the Harvard TH Chan School of Public Health.
7. Master Cleanse
This liquid-only diet involves drinking a mixture of water, lemon juice, maple syrup and cayenne pepper for 10 days, and Beyoncé reportedly used it to lose 20 pounds in two weeks for her role in the 2006 film. Dream womenreported USA today. Liquid or juice diets were having their moment, with the purported benefits of weight loss and detoxification. But juice fasts don’t provide enough nutrients, and any weight loss is likely temporary when you start eating solid foods again, according to Mayo Clinic. And remember: you have organs, specifically the liver and kidneys, that naturally detoxify your body.
8. Heel30
You can tell from the 30 in the name that Whole30 is a fad diet: it’s an elimination diet designed to be done for 30 days. The diet, developed in 2009, according to the Whole30 website, has strict rules about what you can and can’t eat, and if you don’t stick to them, you have to start over. The emphasis is on healthy foods, such as meat, seafood, eggs, vegetables, fruits and healthy fats, while avoiding all added sugars, alcohol, grains, legumes and dairy products. Although it is popular—and tests your mettle for following a strict diet—there are no observational studies or randomized, controlled trials that support the benefits of Whole30 or compare how effective it is versus other weight loss diets. reports research.
9. Low-fat diet
Remember when SnackWell’s fat-free cookies were the healthy choice in the 1990s? That was at the height of the low-fat craze, when people tried to lose weight by eating foods that fell into the low- or no-fat category, such as fat-free salad dressings, chips and frozen yogurt. The whole low-fat era spanned decades, notes the Harvard TH Chan School of Public Health, but now health experts are recognizing the value of foods that contain healthy unsaturated fats, and we’ve moved away from the low-fat craze. “In general, to be a healthy human being, we need some fat,” says Smolen. Fats not only provide energy, but also help your body produce hormones and absorb fat-soluble nutrients that your body needs to function properly, she says. Fat contains more calories per gram than protein and carbohydrates, so reducing some fat in your diet can help you eat fewer calories and lose weight. But just because something is labeled fat-free, low-fat or low-fat doesn’t automatically mean it’s healthy.
10. Special K diet
When the Special K diet came out in the early 2000s, the goal was to lose two jeans sizes in two weeks by eating Special K for breakfast and lunch, and then a regular dinner. (In later iterations, you could eat specialty K products, like bars, instead of cereal.) It’s a low-calorie plan that was never designed for the long term, but somehow it felt achievable when you just had to to make. it by a few weeks. On the plus side, Rifkin points out that because not much attention is paid to the diet and you eat largely the same thing every day, it can be easy to follow. Yet two weeks can seem like an eternity. “There is a lack of variety, and many people get bored easily,” she says, adding that adequate nutrition is lacking. This is another fad diet to skip.