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These days, you can’t walk down the grocery store aisle without seeing foods labeled Paleo, Keto, Whole30, gluten-free — the list goes on and on. But what exactly are fad diets, and why should you care (or not care!) about them?

Consumers get bombarded with messaging about trends in nutrition on social media, in commercials, and in books, and much of the time, the advice is conflicting.

One day, eggs are great to eat. The next day, you’re told to avoid them. Red wine has health benefits, but drinking too much is bad for you. Coconut oil is a miracle food, but it’s also really high in saturated fat, which can increase your LDL (bad) cholesterol.

Fad diets are diets that are trendy in the short term, even though they’re often not based on scientific research or evidence. That hasn’t stopped the industry from taking off. In 2020 alone, the U.S. weight-loss industry was valued at $71 billion.

Fad diets often encourage deprivation and the demonization of foods, which may lead to nutrient deficiencies and disordered eating habits. They also focus on quick results — and almost always on weight loss.

There isn’t quality clinical evidence to back up the safety or efficacy of most fad diets.

Same thing for juice cleanse diets that supposedly “detox” the body. Your body already has a detoxification system: your liver and kidneys.

Even well-studied diets have been co-opted by the weight-loss industry and sold to people as quick fixes.

The ketogenic or keto diet, for instance, is an effective alternative treatment option for people with epilepsy who don’t respond to traditional antiseizure medications or aren’t good candidates for surgery.

The diet also has some potential benefits like improving heart health, but it comes with several potential side effects. In the short term, you may experience what’s known as the “keto flu,” which can cause temporary symptoms such as:

  • fatigue
  • dizziness
  • nausea
  • vomiting
  • constipation
  • low exercise tolerance
  • headache

If you stick to the diet in the long term, your risk for developing the following may increase:

  • fatty liver
  • kidney stones
  • vitamin deficiency
  • low protein levels

And the diet may not be suitable for people with certain health conditions like type 1 diabetes.

Another trendy food lifestyle is the gluten-free diet. Even though a gluten-free diet is necessary for some people, most don’t need to eliminate gluten from their diet to be healthy.

A 2019 double-blinded randomized controlled trial — the gold standard for research — showed that gluten doesn’t induce gastrointestinal symptoms in healthy people.

Like any other diet, it’s important to be well-rounded and consume a variety of nutrient-dense foods. And for some people, skipping gluten-containing products without guidance from a registered dietitian may actually be harmful.

Money motive

You can better your health without focusing on weight loss. Plenty of lifestyle changes and habits can improve health markers like blood pressure and heart health — walking, cooking more at home, getting quality sleep, reducing stress levels, for example.

However, fad diets are money makers, so companies make promises to bring in the big bucks. People are often duped into buying the latest “weight-loss” product or book only to spend even more money trying the next fad.

Instead of throwing your money away on supplements, books, and products that don’t work, invest in your health by making small, sustainable changes.

Here’s why fad diets probably won’t do much for your health in the long term.


A calorie deficit promotes weight loss. But depriving yourself of the foods you enjoy to cut calories is likely to backfire.

And while fad diets may help you lose weight in the short term, they’re hard to stick to in the long run because of their restrictive nature.

It’s also important to understand that bodyweight is just one piece of the larger puzzle that makes up a healthy person. Emerging research also suggests that weight may not have as big an impact on health as experts once believed.

If you’re concerned about being healthy, a recent study suggests that physical activity may be more important than weight loss.

Of course, your diet and body weight can impact health markers like blood pressure and cholesterol, but making weight loss the end-all-be-all goal might not be the best strategy.

And relying on a quick fix like a fad diet might cause more harm than good.

Certain restrictive diets may increase the risk of developing eating disorder tendencies in people of all sizes.

And while a quick-fix diet might improve health markers in the short term, unless you’re changing your habits for the long haul, those improvements, like better blood sugar control, may not be long-lasting.

Moreover, restriction can lead to cravings. Researchers are still trying to understand food cravings, but completely cutting out chocolate, potato chips, or ice cream can lead you to want those foods more than ever. Deprivation isn’t a viable long-term solution because it’s not sustainable.

The restriction mindset can lead to binging and further restriction — an unhealthy cycle that can cause weight-cycling, which is associated with a higher risk of disease and mortality.

There’s also a potential association between restrictive dieting and the development of eating disorders.

Removing your favorite foods also takes away a lot of pleasure in eating. It’s possible to enjoy the foods you love and still reach your health goals.

One of the principal tenets of Intuitive Eating, for example, is gentle nutrition, the concept that you can eat healthfully while honoring your taste buds.

Nutrient deficiencies

Often, certain foods or macronutrients become the target of fad diets. But if you’re required to cut out an entire food group, the diet probably won’t last. You may also be at higher risk for nutrient deficiencies.

Cutting out foods and food groups, or significantly reducing caloric intake, can make it much harder to get the nutrients your body needs.

For example, people following a strict vegan diet are at risk for vitamin B12 deficiency because the nutrient is found primarily in animal foods.

And if you eat a very low carb diet, like the keto diet, you may not be getting enough fiber or other key vitamins and minerals, which can lead to unpleasant side effects like constipation and muscle cramps.

Unnecessarily demonizing certain foods

Your diet doesn’t need to involve an all-or-nothing approach. Some foods are more nutritious than others, but all foods can be a part of a healthy diet. We live in a world of delicious options, after all.

Of course, too much of a tasty thing may negatively impact your health. Large quantities of refined carbs, for instance, can cause blood sugar spikes that may eventually lead to diabetes. They may also contribute to the development of heart disease.

Carbs aren’t the enemy, though. You can reduce your refined carbs and sugar intake without going to the extreme. Whole grains, fruits, vegetables, and legumes contain plenty of nutrients, including fiber, which is essential for gut health.

Disordered eating

Diets can also negatively impact your mental health.

Fad diets, in particular, are associated with an increased risk of disordered eating and eating disorders due to their restrictive nature and negative impact on body image.

There’s also the mental toll of restriction to consider. Constantly striving to “eat perfectly” can cause unnecessary stress, which may, in turn, affect your overall health.

Are you looking to improve your overall health? Here’s what to try instead of that popular fad diet that’s all over your social media feeds.

Be consistent

Eat consistently throughout the day to help maintain optimal blood sugar levels, prevent indigestion, and curb uncomfortable bloating.

Eat balanced meals

Aim for your meals to include lean protein, carbs high in fiber, and healthy fat. Not only will this help you eat a variety of nutrient-rich foods, but it’ll also stabilize your blood sugar and promote a healthy gut microbiota.

Focus on adding instead of taking away

Eat more fruits and veggies! Aim for 4–5 servings daily. What’s a serving? One cup of leafy greens, 1/2 cup of cooked veggies, a piece of fruit about the size of a tennis ball, or about 1 cup of berries.

If that sounds like a lot, start slow and add a serving to one meal or snack. Remember that canned, frozen, and dried produce count too, but try to opt for ones with no or little added sugar and salt.

Be mindful of added sugar

The American Heart Association recommends less than 25 grams for women daily and less than 36 grams for men, but it’s a good idea to keep added sugar intake as low as possible for optimal health.

You’ll find added sugar in sweet foods, like cookies and ice cream, but it’s also in many other foods like bread, crackers, and yogurt. Added sugar shows up on food labels under various names: honey, agave, invert sugar, sucrose, and fructose. Try to choose lower sugar options when you can.

Read more about added sugar.

Enjoy foods you love

Complete deprivation doesn’t work. If you’re worried about sugar intake, having some dessert every night may help curb intense sweet cravings.

Restrictive diets tell you never to have dessert, leading to cravings and binging. Because you tell yourself you’ll never eat cookies again, eating one cookie can turn into eating a whole box.

Allowing yourself to enjoy the foods you love without the guilt — whether that’s chocolate, ice cream, or cookies — can absolutely be part of a healthy diet.

Get moving

You don’t need to start doing high intensity workouts at 5 a.m. to improve your health.

Getting in at least 150 minutes of moderate intensity activity each week can significantly reduce your risk of heart disease and stroke. That’s just over 21 minutes a day and can include any activity that gets your heart rate up, including brisk walking and household chores.

Regular exercise is also good for your bones and can help improve your sleep quality. Moving your body can also have a positive impact on your mental health.

Get professional advice

If you’re feeling super confused about how to incorporate healthy habits and feel overwhelmed by diet culture nonsense, consider seeking out a registered dietitian to help you break down health advice and sustainably achieve your goals.

Some professionals like Healthy at Every Size (HAES) or anti-diet dietitians even embrace an anti-diet culture philosophy.

A fad diet might help you achieve your goals in the short term, but cutting out major food groups and your favorite dessert isn’t sustainable. Making smart, healthy choices without focusing on weight loss and relying on quick fixes is possible.

Need help parsing the contradictory health advice out there? Talk with a qualified expert like a registered dietitian.