Hungry Runner? Subscribe to get your Hunger Scale for Runners


7 Reasons Why Fad Diets Don’t Work

Here is the science behind why fad diets don’t work. There are things you can do to change your unhealthy relationship with food and improve your health and well being without fad diets. 

Do you have a love hate relationship with food? What about with your body? Let’s talk a little about that today along with the disadvantages of dieting. 

As an Amazon Associate, I may earn from qualifying purchases. You can read more here on our Disclaimer and Privacy Page.

It’s no secret I’m against people purposefully restricting their food. It’s the theme of our Better Than Dieting Challenge each January and it goes against everything in Intuitive Eating

I’ve just started reading Anti-Diet by Christy Harrison, a new book that came out this year. It’s been fascinating so far because it goes into the history of dieting.

The book will continue to break down why diets don’t work and food restriction goes against what our bodies are wired to do. It also greatly touches on weight stigma, what we know about weight stigma, and how that can be damaging to health in and of itself. 

Why Fad Diets Don’t Work

You may be wondering, do fad diets work?, and inncocently hoping they do, however let’s discuss why fad diets don’t work.

Think back to the last time you embarked on a diet, or even the wellness diet, a diet in disguise. Did it work? Did you maintain weight loss, or gain it all back?

Maybe you gained it back and then some. That’s actually completely normal, as in the majority of people gain the weight back (1)

If you look at studies beyond the year mark or two (which are rare), that’s when people start regaining the weight. This is an important distinction. 

Weight cycling, the repetitive pattern of weight gain and weight loss (also known as “yo-yo dieting”, is actually more damaging to our health (2). 

The diets failed you, not the other way around.

Diets Come to An End

The very nature of a diet has a start and end point, whether it’s a temporary hyperfocus on food before a wedding, before a conference, before the school year, etc. Fill in the blank.

People understand they are temporary and not sustainable. If they were sustainable, we’d be able to follow them forever and be happy.

And let’s be honest – no one is happy on a diet. It’s typically a miserable, isolating experience that affects more than just your relationship with food.

So, what can you do instead of fall into diet culture?

graphic of scale with text overlay about weight cycling

Dieting Affects More Than Your Relationship with Food

This is a BIG one, and the premise of My Hunger Ebook, How to Learn To Honor Your Hunger Again.

Consider how your social life changes on a diet. Perhaps you can’t eat at the same establishments, or going out with friends for appetizers and cocktails gets a little harder.

Changing your unhealthy relationship with food takes time, and intuitive eating is the way there. 

learn how to honor your hunger Ebook

Perhaps you think twice about going to your niece’s birthday party because you know cake is your kryptonite and you can’t say no to it. 

Dieting affects our overall well-being. It affects mental health and physical health (more on that below), and can actually cause more gut issues since your body adapts to having less food and digestion. 

Furthermore, the act of dieting takes up

It puts you in a constant battle with your body for not being “good enough” or measuring up to diet culture’s unrealistic expectations. 

Social media graphic with text about dieting taking up mental energy and space

Diets Create a Hyperfocus and Obsession Around Food

Not only does dieting take the pleasure and enjoyment out of the food experience because it’s so rigid, but it creates an obsession around food.

Foods are deemed “good” or “bad.” There are foods you can eat and unsafe foods. It becomes easy to obsess about the what and the when.

There is a hyperfocus around food because you’re not getting enough so your body fixates on what it wants and needs. This lights up reward centers in the brain.

assortment of a dozen donuts in a to go box

If you’ve been on a diet or are trying to restrict food (or follow “keto” or “low carb”), have you found yourself on Pinterest just staring at images of food? Or drooling over food photography in food magazines?

This is one reason why I never promote low carb diets or low carb diets for runners

There’s a reason for that. Our hormones kick in to make you want food more, and to make the food taste better. Your body and brain know you need more fuel and this is the one way they know how to manifest that. 

Dieting also increases another hormone called cortisol, our stress hormone (3).

Cortisol is actually linked to:

  • inflammation
  • weight gain
  • increased food intake
Social media graphic about dieting hormones making food taste better

This study, published in the journal Obesity (a problem in and of itself), talks about the increase in appetite that happens when food is restricted and discusses why long term maintenance of a smaller body size and weight is so difficult (4). 

Again, it’s not you. It’s the diet. 

Furthermore,  people who engage in extreme restriction (cutting out whole food groups and sticking to intense diets for long periods) are 18 times more likely to develop an eating disorder than non-dieters.

Diets Are Based on External Rules

Diets don’t teach you lifestyle habits. They teach you external rules to live by, rather than encouraging you to check in with yourself.

Rather than encouraging you to follow your innate hunger and fullness cues and signals, they encourage following strict rules that may include eating when you’re not even hungry and stopping before you reach fullness and satiety. 

But, what dieting is really doing is increasing ghrelin, your hunger hormone, because your body is focused on survival. Yet, these external rules tell you not to listen to this hunger. 

So, eventually, your body shuts down and stops giving you the hunger signal altogether.

Dieting has taken you completely out of your body and ruined any intuitive nature you could have of listening to your body. 

Social media graphic about food obsession with text overlay

This can be repaired but it does take time. 

All of this obsessing takes you away from the intuitive nature of your body. Instead of listening to your body, you’re listening to external foods rules set by who knows who?!

  • Who knows how big of a portion size you need?
  • Who is to say that you should stick to this many calories a day?
  • Why should you be eating the same amount as the person next to you?
  • What does diet culture know about your stress, your biological needs, your exercise, your cravings, your body?

Diets Don’t Take Individual Differences Into Consideration

Another reason fad diet’s don’t work – We all have different needs, no matter what diet culture tells us.

As individuals, we all have a different genetic makeup. We work differently, we exercise differently, we sleep differently. And yes, we also all eat differently. 

The wellness culture forgets to talk about this piece. 

stepping on scale that says help

There is no way there could be a blanket recommendation or “plan” that could work for all of us and provide the same results. It’s preposterous. 

Plus, can we consider that dieting is a 67 billion dollar industry? Not only is it failing you, but it’s taking a good chunk of your disposable income while doing so. 


Diets Can Lead to Nutritional Deficiencies and Even Malnutrition

A 1,200 calorie a day meal plan isn’t going to benefit anyone, except maybe my toddler because that’s the amount of food she needs in a day

A grown adult needs much more. Plus, 1,200 calories can’t provide all the nutrients you need. Fad diet statistics won’t tell you that, but scientific knowledge of the body will. 

Whether you are skipping out on food groups entirely, or just greatly reducing the amount of food you take in, there is usually a mismatch in what your body needs and what you’re actually giving it.

And just relying on supplements and additional vitamins and nutrients isn’t the answer. 

Social media graphic about skipping out on food groups

Many of us know dieting isn’t doing us any good, as some of the most common google searches are, “how to lose weight fast without dieting,” or “how to lose weight without exercise or diet.”

But, what we’re still missing is the fact that we don’t have an evidenced-based way to promote that and what we really need is body acceptance and understanding that health is more than what we weigh.  

Dieting Slows Your Metabolism

Dieting makes your metabolism more efficient, meaning it burns less calories. It makes sense because you’re taking in less energy overall, so your body adapts to using less energy as well. 

As you can guess, having a slower metabolism actually makes it harder to lose weight and easier to gain weight. This is why so many diets fail (you don’t fail, the diets do)! 

The biological response to dieting is not what the fad diets tell you or what culture tells you. 

  • Consider the Biggest Loser Study, published in 2016. This study followed participants of The Biggest Loser show and tested their metabolisms (through their resting metabolic rate) both after the show and then again six years later (5).
  • Six years after dieting, the mean decrease in metabolism for 14 of these participants was nearly 500 calories a day. Meaning, their metabolisms burned 500 calories a day LESS than before they started dieting.
Social media graphic with text overlay

Imagine having to eat 500 calories less a day for the rest of your life to maintain your weight?

Furthermore, the participants with the greatest weight loss at the end of the competition also experienced the greatest slowing of RMR at that time. 

This is how the body works, but diet culture doesn’t tell us this. 

How to Stop Dieting and What to Do Instead

The whole premise of intuitive eating is to learn to get back in touch with your innate cues and body signals, everything diet culture takes away from you. 

Here are some great starting points for learning how to stop yo yo dieting. 

  • Evelyn Tribole and Elyse Resch have done a fantastic job in creating the 10 principles of intuitive eating and explaining a concept so “natural.” They just published an updated 4th edition of their book.
  • I also highly suggest the intuitive eating workbook, which shares practical worksheets and examples.
  • Another thing to check out if you’re sick of dieting is the Health at Every Size (HAES) movement. While some people mistakenly call it “Healthy at Any Size,” what it’s really focused on is supporting people of all sizes in addressing health directly by adopting healthy behaviors and finding compassionate ways to take care of themselves.

This post is getting long, so I think it warrants a future post about how to stop dieting and eat normally and how to start intuitive eating. 


  1. Mann, T., Tomiyama, A. J., Westling, E., Lew, A. M., Samuels, B., and Chatman, J. (2007). Medicare’s search for effective obesity treatments – Diets are not the answer.  Psychol.62, 220–233. doi: 10.1037/0003-066x.62.3.220
  2. Strohacker, Kelley, Carpenter, Katie, McFarlin, Brian. (2009). Consequences of Weight Cycling: An Increase in Disease Risk? Intl Jour of Exercise Science. 2(#):191-201.
  3. Tomiyama AJ, Mann T, Vinas D, Hunger JM, Dejager J, Taylor SE. Low calorie dieting increases cortisol. Psychosom Med. (2010) 72:357–64. doi: 10.1097/PSY.0b013e3181d9523c
  4. Polidori D, Sanghvi A, Seeley RJ, Hall KD. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake.  2016 Nov;24(11):2289–95. doi: 10.1002/oby.21653.
  5. Fotherfill Erin, et al. Persistent metabolic adaptation 6 years after The Biggest Loser competition. Obesity: A Research Journal. 2016 May;24(8):1612-1619.
Join The Conversation

More For You!

Share Your Thoughts

Your email address will not be published. Required fields are marked *

  1. Yes. Yes to all of this. I wish I could shout it from the roof tops when I hear people talking about not eating carbs or only eating X calories. Sadly some people think it’s more beneficial for them since it worked for Sally.

    1. It is sad that the culture promotes restriction and fad diets. Hopefully, we are slowly making waves in changing that but knowledge is power!