Despite the fact that people are becoming more wary of dieting, fad diets are still everywhere. They’re just hiding undercover, calling themselves lifestyle changes.

As a dietitian who specializes in eating disorders and disordered eating, I see firsthand how much damage these fad diets (and any diet) can do. According to the National Eating Disorders Association (NEDA), a history of dieting is a major risk factor for developing a full-blown eating disorder.

In fact, an old study of nearly 2,000 teenagers found that “severe” dieting (AKA fad dieting) left girls 18 times more likely to develop an eating disorder. Even “moderate” dieting made an eating disorder five times more likely.

In other words, dieting is dangerous. (Plus, it doesn’t work.)

If you think that you might be falling prey to fad diets and their ridiculous claims, here are 4 red flags to look out for.

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1. It involves cutting out long lists of foods or entire food groups.

As it turns out, even less-restrictive diets aren’t sustainable for long-term weight loss.

But diets that involve cutting out food groups (or long lists of foods) will probably lead to failure even quicker and more spectacularly. There’s also evidence, like this 2020 review published in The BMJ, that all kinds of diets — whether they’re low-carb, low-fat, calorie-restricted, whole-foods based, or something else — tend to lead to weight loss in the first 6 months, but that most people don’t maintain that weight loss for a year or more.

In other words: Cutting out food groups will probably lead to quick weight loss, but all of that weight will come back.

2. It makes big promises about weight loss.

While most fad diets lead to short-term weight loss, most people regain this weight within a few years. Be wary of diet plans that advertise success stories, like people who lost a certain amount of weight in a certain number of weeks.

On many diet ads, you’ll notice an asterisk explaining that the “incredible” results they talk about aren’t typical. Generally, diet companies choose outliers — people whose “success” was so much more extreme than anyone else’s — for these ads.

3. It tells you to eat (or not eat) at certain times.

Although time-bound diets like intermittent fasting are popular, there’s not enough evidence to support their safety and effectiveness.

A 2022 review study published in Nutrients pointed out that although there’s some promising research that intermittent fasting could improve certain health markers, most of that research has been conducted in animals, not humans. The authors also explain that studies often don’t take into account the potential negative effects, like how hard it can be to stick to a regimen like this, and the potential for disordered eating.

4. It cites small studies that make big claims.

Lots of fad diets cite bad evidence to support their claims. For example, an elimination diet might cite a study concluding that whole grains are harmful because of certain chemical compounds that block the absorption of certain nutrients. But if you look at all of the evidence on whole grains put together, it becomes clear that this absorption-blocking effect is extremely minimal, and that the benefits of whole grains far outweigh the risks.

The bottom line? Fad diets don’t work, and can actually be really dangerous.

Instead of taking drastic measures in an effort to improve your health, focus on eating a wide variety of foods that actually feel satisfying.

If you’re struggling with an eating disorder or disordered eating, I can help. As a dietitian, I take a weight-inclusive, gender-affirming, patient-centered approach. Learn more about my nutrition counseling, offered to clients in several states. If you’re not ready to commit to counseling but want more information about the anti-diet approach, subscribe to my weekly newsletter.

You might also like:

4 Nutrition Scams to Watch Out For

What Is Orthorexia — And Do I Have It?

Binge Eating When You Start Intuitive Eating? It’s OK.

What Is Intuitive Eating? Why Is it Better Than Dieting?