Why Diets Don’t Work

Written by Rachel Bailey • Reviewed by Emily Fultz, MS, RD, LDN

I said it once and I’ll say it a million more times: Diets don’t work. This is not a new finding, but it is an important one to keep sharing. Diets are sneaky, and they have millions of people coming back for more each year spending billions of dollars. This is our first red flag.

The diet industry makes billions of dollars off of people every year on a product that does not work. Success may come early on when starting a fad diet, but due to the unrealistic goals and nutrient restrictions (often eliminating entire food groups), compliance is a significant concern. Yes, the drastic restriction of nutrients may lead to an initial rapid weight reduction, but there are many health concerns to be weary of. It is also important to understand that the majority of fad diets have not yet been extensively studied, and studies that do exist often have high dropout rates and are sometimes non-conclusive.1

If you have been on a diet before you know that weight comes off and comes back on. This is called weight cycling.2 This roller coaster of weight coming off and back on your body has been linked to many chronic diseases including diabetes, stroke, cardiovascular disease, and altered immune function. 

At this point we are all on the same page, right? No more giving your time or money to these FAD diets that cause guilt and shame! We are here to fuel our bodies in a way that we can sustain for a lifetime. But like I said before, FAD diets are sneaky so let’s review some popular ones so you can get an idea of what to look for when deciding how to eat! 

Intermittent fasting 

This diet gives a time window to when you are able to eat and when you will fast. There are many different variations of this regime, a common schedule to adopt is 16 hours of fasting and 8 hours of eating.3 During this time you are to eat regularly but there are no rules on what types of foods you eat during this time. 

Intermittent fasting takes away and suppresses your hunger and fullness cues. Your body is smarter than you may think and just like it will tell you when you are cold or hot it will tell you when you are hungry and full, if you listen in. There have probably been many things in your life that have taught you to suppress these feelings but you can learn to listen to your body again. There is no one meal plan that will work for everyone so learning how to listen to your body’s cues is a valuable lesson. 

Food can be an important part of people’s social lives and culture. By restricting the time that you can eat food this may force you to miss out on or fully enjoy some of those moments. I encourage you to allow yourself to create positive memories that surround food with friends and family no matter what time of day.

Low Carb

This diet has been known by several different names: Ketogenic diet, Atkins diet, and Whole 30. These are low carbohydrate diets, some allowing different amounts or types of carbs. Within Keto it is recommended that your carbs stay between 5-10% of your daily calories.4 Your brain’s preferred source of energy is carbohydrate,5 so you can imagine that fatigue and lack of focus are some of the main side effects of this diet. 

When a diet tries to eliminate or restrict a macronutrient or whole food group we want to proceed with caution. Carbohydrates, proteins, and fats all have important roles in the body. Turning one of these into a “bad” choice creates an unhealthy relationship with food that can be harmful to the person on the diet and those that surround them because of how they are talking about food. 

A helpful tool

There are SO many diets out there no one can keep up and some are sneaky. So, before you decide what your next wellness change is going to be, ask yourself these questions.

  1. Is this diet cutting out a major food group or macronutrient?
  2. Does this diet give food morality, calling some foods “good” and others “bad?
  3. Is this diet offering a one size fits all option?
  4. Is this diet promising weight loss?
  5. Does this diet take the joy out of eating?

If any of the answers to the questions above are “yes” let’s skip!

  1. Is this change something I can do for a lifetime?
  2. Does this change encourage balanced meals that include proteins, carbs, fats, fruits, and veggies?
  3. Does this change encourage individualized nutrition information?
  4. Does this change encourage you to get in touch with your hunger and fullness cues
  5. Does this change encourage movement that you enjoy?

If the answers to these questions are “yes” this may be a great choice for a nutrition or wellness change that you would like to make. 

If you are curious about a diet that you have seen recently or would like more nutrition or wellness support do not hesitate to reach out! 

As always nutrition is highly individualized so speak to a registered dietitian before making any substantial nutrition changes in your life. 


  1. Tahreem A, Rakha A, Rabail R, Nazir A, Socol CT, Maerescu CM, Aadil RM. Fad Diets: Facts and Fiction. Front Nutr. 2022 Jul 5;9:960922. doi: 10.3389/fnut.2022.960922. PMID: 35866077; PMCID: PMC9294402.
  2. Wolpert S. Dieting does not work, UCLA researchers report. UCLA. https://newsroom.ucla.edu/releases/Dieting-Does-Not-Work-UCLA-Researchers-7832. Published May 10, 2019. Accessed October 31, 2022. 
  3. Intermittent fasting: What is it, and how does it work? Intermittent Fasting: What is it, and how does it work? | Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work. Published October 20, 2022. Accessed October 31, 2022. 
  4. What are fad diets? learn healthy eating from a registered dietitian: Kelly Powers, MA, RD. Kelly Powers. https://www.kellyepowers.com/what-are-fad-diet. Accessed October 31, 2022. 
  5. Slavin J, Carlson J. Carbohydrates. Adv Nutr. 2014;5(6):760-761. Published 2014 Nov 14. doi:10.3945/an.114.006163

One Comment on “Why Diets Don’t Work

  1. Pingback: Social Media, Body Image, and Diet – Nutrition Counseling

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