Are You Being Seduced by Fad Diets? 3 Ways to Know

Have you ever seen those commercials in which a beautiful, scantily clad woman suggests you ask your doctor about Viagra? I’ve been thinking about those a lot. As a dietitian, my job has very little to do with erectile dysfunction. So what do these commercials have to do with my job? Fad diets, my friends. 

Obviously, no one is asking me for professional help in achieving liftoff. But I am receiving more and more requests for diet prescriptions (you know, the whole "ask your doctor..." angle). Here's an example, which is a composite of several inquiries I’ve received: 

Prospective client: “I’d like your help in designing a keto meal plan for weight loss, optimal energy, and peak athletic performance.”

Me: “Thanks so much for your interest in working with me. I’d love to help you, but I don’t feel comfortable writing keto meal plans at this time. Until strong evidence proves me wrong, I’m simply not convinced that it’s sustainable or effective for performance and long-term weight loss. But I’d be happy to discuss my approach with you.” 

From here, I’ve seen a couple of different outcomes: 

  1. radio silence
  2. a reply filled with pro-keto propaganda (because that will change my mind after five years of dietetics school and a couple of years in practice). 
  3. (the most common) a request for a dietitian that will make all the prospective client’s keto dreams come true. Because prospective client has seen so many people just like him on the internet who've gotten ripped on keto. 

This scenario is not exclusive to keto—I’ve received inquires from prospective clients asking me to co-sign a variety of fad diets ranging from lectin-free to the cabbage soup diet. I’m not likely to do that (sorry). In private practice dietitian world, that scantily clad Viagress is a sexy fad diet that keeps popping up in your news feed, promising quick weight loss and boundless energy. 

Fad diets are the bane of an RD’s existence. To be clear, I’m not blaming those prospective clients. I’ve had times when I’ve been up a few pounds, and a quick fix sure is tempting. Fad diets RARELY WORK (at least, long-term)! Yet, it blows my mind how quickly they become popular. 

How does that happen? How do fad diets come to be? In this post, I’ll discuss three ways in which diets become fads.

1. Sources of (Mis)information

Have you seen this meme circulating around instagram? 

Help Wanted


I chuckle a bit every time I see it because it is SO TRUE! 

Most Americans turn to mass media for nutrition information. A 2011 survey (n=754) conducted on behalf of the Academy of Nutrition and Dietetics found that:

  • 67% of respondents turn to television for information about diet.
  • 41% of respondents obtain diet information from magazines. 
  • 40% of respondents look to the internet (I’d guess this has increased quite a bit).
  • 20% of respondents learn about nutrition from newspapers. 

Want to know how many of the respondents in that survey solicited diet advice from a dietitian or a doctor? One percent and 16%, respectively. But here’s the thing. Nutrition can be really freaking confusing and, unfortunately, the rabbit hole of internet searching rarely brings clarity. 

Take the PURE study. Since it’s publication in 2017, thousands of articles and blog posts have proclaimed that we’ve been getting diet wrong for all these decades—that high-carbohydrate, low-fat diets are to blame for disease and mortality worldwide. 

There are a couple of problems, though: 

  1. Most of the people in the study were from low-income countries 
  2. Most of the people in the study ate very high carbohydrate diets (much higher, in terms of percentage of calories from carbohydrates, than recommendations for healthy Americans). 
  3. Not only did participants consume very high carbohydrate diets—the bulk of their diets were low-quality, highly refined carbohydrates that are known to cause health problems.
  4. PURE is an observational study, which looks at correlation and not causation. In other words, the data from PURE can’t prove that high carb diets increase mortality.

Yet, if you Google “PURE study” some of the top headlines seem to advocate for lower carb, higher fat diets:

  • “PURE Shakes Up Nutritional Field: Finds High Fat Intake Beneficial” 
  • “PURE Investigators: Rethink Diet Guidance to Plug More Fats, Fewer Carbs”

So why do many bloggers and reporters take this angle?  In part, because a healthy diet—one that promotes health and supports your long-term goals—isn’t sexy. Readers like novelty. Headlines that flip conventional diet wisdom on its head attract readers! These ideas only spread like wildfire among nutrition hobbyists and bloggers. 

Read with caution, friends (or even better—go straight to trained professionals). 

2. Big Promises (Sometimes Based on Pseudoscience)

“Lose 50 pounds or more without feeling deprived!” 

“Drop 3 pants sizes in 2 weeks!”

“Get the body of your dreams on DietX!”

I want the body of my dreams as much as the next girl. But fad diets consistently overpromise and underdeliver. 

You may lose some weight at the beginning of your fad diet. Consider diets that have low-carb “induction phases” or jumpstarts. These induction phases exist, in part, so that followers see quick results. Success begets success, and quick results breed enthusiasm for the diet. 

Consider low-carb approaches. A lot of fad diets are lower carb by design, especially in the beginning. If you reduce your daily carb intake, you probably will lose some weight! This is because the body hangs on to about 3 grams of water for every gram of glycogen (which is the storage form of carbohydrates). When you eat fewer carbohydrates, you store less water in your muscles. Thus, some or all of the weight you are losing is water weight. Sadly, it will creep back on if you increase carb intake. 

And even if you lose some fat on a lower carb diet, it’s not because carbs are the devil. Water weight dissipation aside, there’s no magic to low carb. The weight loss happens because there is a calorie deficit. It’s no better than a “boring” old low-fat diet for weight loss. 

named diets

To be clear, I’m not necessarily endorsing a low-fat diet over a low-carb one. The best diet for a normal, healthy person is the one he can stick with long-term. Just keep in mind that many fad diets (keto, Paleo, etc.) tend to be lower carb by design, because lower carb diets shed water weight. 

Similarly, there's no specific magic to most diets that cut out entire classes of foods. You just eat less. Diets that promise rapid weight loss, Herculean strength, and pure magic are probably too good to be true. 

3. A Rabid Following

By virtue of point one and especially point two, many fad diets develop a zealous fan base. A fan base is the scantily clad woman in those Viagra ads.

I’m not going to name any diets. But a couple, in particular, have online communities that are very interesting for a dietitian who wrote a rhetorical criticism for her master’s thesis. 

Sure, these communities provide support. But they’re sometimes dangerous and/or downright vicious.  I’ve seen frustrated posts that a diet isn’t delivering on its promises, with curt replies questioning the poster’s commitment/dedication/intelligence (I always wonder if these respondents are hangry). 


A quick scroll through those forums often yields at least a few posts from people who’ve “messed up” a meal or, worse, completely “fallen off the wagon.” Certain programs require that you completely start over…for one little slip up! And boy, do the people in these communities let you know about it. 

Look. You don’t win a goshdarn prize for having a perfect diet. It doesn’t win you friends, or influence, or make you a better person. Yet, fad diet forums are often populated with people who play high and mighty about their dietary compliance. Reading through them can make you feel like crap, if you’re someone who likes to live a little.  It’s really, really easy for some people to fall into a diet community—particularly those who are perfectionists or who have a desire to belong to a group. 

A boring, healthy diet is an act of rebellion in a time of fad diets with rabid followings. Find something that works well for you, stick with it, and give yourself some grace when you have an off day! Invest time in making simple changes that promote long-term health—not on scrolling the internet for quick fixes. 

Hopefully this post will make you think twice when you're being seduced by a fad diet. Be leery of big promises, read news stories with a careful eye (here is some great advice!), and find what works best for you! Or, even better, seek out a dietitian or a doctor who can help you meet your goals.