Why Diets Fail (or succeed)

What are the actual Diet Failure/Success Rates?

Many of us have heard the notion that only 5-10% of people succeed on a diet. But, as it turns out, this statistic is not at all accurate. Those numbers came from a study of people that weren’t representative of the entire population...those that were much more likely to fail than the average person.

The reason it seems like so many people are failing is because those are the only stories you ever hear about. Most people who have successfully stuck to a diet aren’t the ones telling their story on a commercial, going on about the number of diets that have failed them in the past.   

The actual diet success rate is closer to 30%, with “success” being clinically defined as maintaining weight loss of 10% below your initial weight for several years.

That’s not to say that a LOT of people succeed. In fact, not even the majority succeeds. But success is possible for more people than you think.

This false idea that only 5-10% of people succeed on a diet may be creating a psychological expectation for failure amongst people starting a new diet. Basically, they’re going into it expecting to fail.

How we fall into the Cycle of Success & Failure

Another problem is that the first part of a new diet is always the easiest. In the early stages, weight and fat tends to fall off with minimal struggle. But as it gets more challenging later on, and the necessary effort increases, people tend to give up.

When they think back on the diet, all they remember is the initial easy part…when the weight loss came quickly. They go back into the diet expecting the same thing to happen again. But (surprise, surprise) at a certain point, it gets hard again…and so begins the endless cycle of dieting and quitting.

Only remembering the easy phase of a diet inherently leads us to believe that diets are supposed to be easy, quick and painless. And this idea is reinforced by all the ads for products and programs promising rapid weight loss, magic pills and non-restricting diets.

And weight loss shows like The Biggest Loser and Extreme Weight Loss aren’t exactly painting a realistic picture of what “success” is either. When contestants are losing 15/20lbs a week, people start believing that is the norm. Then, when they lose 2/3lbs a week, they feel like a failure (and wrongly so).

Common Dieting Missteps

A common reason many diets fail is because people set unrealistic goals for themselves. You cannot expect to change your eating habits overnight. 

Lots of people jump right into a crazy restrictive diet. But the reality is, if you ease your way in and start making smarter choices one by one, gradually building yourself towards healthier eating habits, it’s much easier to stick to it.

And by all means, stay away from crash diets! There is always a wide array of crazy crash diets claiming they can help you shed weight right away. But the trouble with crash diets is that, while they may help you lose weight initially, you just end up gaining it all back as soon as you return to your old diet.

Inherently, a diet cannot be successful unless it becomes a lifestyle.

Perhaps the largest problem is that when people hear the word “diet” they automatically think of it as something that is short term. But the truth of the matter is short-term diets will only warrant short-term results.

Tips for Success

Those that succeed at adhering to a healthy diet usually live by these tips.

  • Set goals that are specific, measurable, attainable, realistic and timely.

  • Make sure changes to your diet are making you feel more energized, light and happy, not making you feel fatigued, tired and grumpy. Healthy changes to your diet should leave you feeling better, not worse.

  • Don’t get too hung up on fad diets. Amidst all the fads, the things that remain tried and true are portion control, healthy eating and being physically active.

  • Surround yourself with supportive people that will help you reach your goals instead of pressuring you to fall off the bandwagon.

  • Turn your diet into a lifestyle, not something you do for a time and then stop.

It’s important to remember that successful dieting goes beyond science. In many ways, it’s just as much related to the psychological component.


Justus, Nicole. “14 Reasons Why Most Diets Fail.” TheDiabetesCouncil.com, 28 Mar. 2018, www.thediabetescouncil.com/why-do-most-diets-fail/.

McDonald , Lyle. “The Causes of Diet Failure Part 1 -.” Bodyrecomposition, 3 July 2016, bodyrecomposition.com/fat-loss/the-causes-diet-failure-part-1.html/.

Sass , Cynthia. “5 Reasons Most Diets Fail Within 7 Days.” Health.com, 19 Sept. 2013, www.health.com/nutrition/5-reasons-most-diets-fail-within-7-days.