Why Do Most Diets Fail?

By Ali Luke

I’m sure many readers will have experienced a diet that “failed” in the past. These are often ones which you manage to stick with for a few days, even a week or two, then give up on. Usually, the diet was impractical or you just weren’t feeling committed to it.

Sometimes, though, a diet seems successful: you follow the plan for a set period of time, you reach a goal weight, you fit back into those jeans. But then, just when you think you can relax, the diet fails. How? You put back on all that weight you lost.

How many diets fail?

The picture, unfortunately, isn’t good: estimates of the number of diets which fail is typically given as about 95% (the most conservative estimates put it at about 80%). “Failure” means that a dieter successfully lost weight, but didn’t manage to keep it off for as long as a year. Some reports suggest that only 1% of dieters manage to lose weight permanently.

Some types of diets are more likely to result in long-term failure than others – particularly strict plans that involve eating under 800 calories per day (known as Very Low Calorie diets) and diets which change eating patterns radically (replacing meals with milkshakes or cereal bars).

Why do diets fail?

The most common reasons why diets fail to result in long-term weight loss are:

  • The dieter followed a plan which didn’t help to re-educate his/her eating habits
  • The dieter ate well below the minimum calorie guidelines during the diet

What’s your reaction when you reach a milestone or goal and finish your diet? Do you go back to “eating normally”? The problem here is that, for most of us, our normal pattern of eating is what resulted in our weight gain in the first place …

What are the problems with a failed attempt to diet?

There are two key reasons why a failed diet is bad for you. The first is psychological; it’s very demoralizing to put in a lot of effort, successfully lose weight, then undo all that hard work. If you felt elated and proud at achieving your weight loss goal, you’re likely to feel disappointed or even angry with yourself for allowing it to slip away again.

The second reason is that “yo-yo dieting” is bad for your body. Any benefits from the weight loss are negated by piling the pounds back on … and this can make it harder to lose the weight again in future. Some people gain back more weight than they lost, putting themselves in an even worse position.

What sort of diets don’t fail?

If you want your weight loss to be for good, not just until you’re back from holiday or the wedding’s over with, then follow a diet plan with the following features:

  • Your diet should consist of balanced, nutritious meals – not endless bowls of cereal or soup, or “meal replacements” such as shakes or bars.
  • Your diet should be made up of foods which you like and which you would eat even if you weren’t on a diet
  • Your diet should re-educate your eating habits. For example, you might learn to cook with a little spray oil rather than tablespoons of oil.
  • You should be exercising as well as dieting: getting active helps you to burn off fat, but the muscle you build will use more calories even when you’re at rest.

Over to you … have you managed to lose weight in the past, only to pile it back on? What are you doing to make sure you succeed – long-term – with your diet?


  1. Jim Cabeceiras

    People who succeed, long-term, in losing and maintaining their ideal weight, have three things in common:

    1. First, their decision to act was born of inspiration, not motivation. Losing weight for your spouse, to look good for an up-coming event, or by hiring the best personal trainer in town – are all temporary motivators. You have to a reach an ’emotional tipping point’, where you decide to take action with no pre-conceived concept of an ending date.

    2. The thirst for knowledge. The desire to re-educate. Not just on valid nutrition and exercise principles, but the solutions to overcoming all barriers to success – like food addiction, stress, the need to identify, and the isolation that often comes with a new eating lifestyle. Successful dieters know how to diminish the influence of old habits and how to confront past barriers – like failing to develop the habit of exercise.

    3. Lack of knowledge about changing behaviors. Developing a new, stressful habit, like eating fewer calories, is in direct conflict with the subconscious, but can be overcome
    through repetition. The successful dieter commits to small changes over several months, where the conscious, stressful efforts of today are eventually replaced by subconscious skills. Developing a new eating lifestyle is a SKILL! You have to commit to practice – usually for a minimum of six months.

    Once you understand these three common issues, you understand why 95% of all diets fail.

  2. Scotty123

    Whole foods are the best way to loose weight and keep it off. Any time you eat processed food it will spike your the sugar in your blood and your body releases insulin to control the sugar and store it as fat. That is why these low fat diets do not work. If you look at these so called healthy diet snacks on the market you may find high fructose corn syrup with in the first few ingredients. This can be disastrous to any one trying to lose weight.

    If you are to eat grains, the best ones are brown rice and oat meal. I believe in a balanced diet. I stay away from all sauces and only use vinegar and olive oil on salads. I eat four to five meals a day, I make sure these meals in clued 20 to 30 grams of protein, medium to high fat dairy, fruit or grains, and vegetables. I do not count calories, I eat until I am full.

    I started this a month ago and lost six inches on my waist line. I feel I am not on a diet because I feel stuffed silly all day.

  3. Richard

    Losing weight and keeping it off is not as hard as people think if they have a good plan for both phases and stick to it. I dropped 10 pounds in 15 days on a 1200 calorie plan. I am in the higher end of my healthy weight range and will lose another 15 pounds in about 45 days or so. This time I have a good plan and I will not go over my high range. And I have not exercised at all. Exercise is good for strength and flexibility but its all about the calories in for fast weight loss and a good plan to keep it off.

  4. Rachel

    I hate hearing stories on how people lose weight and then gain it back.

    It’s so simple. A diet is what you DO eat, ot what you don’t.

    Ps: No so called ‘fad diets’ work.

  5. Tina

    Wow, you sound like many of us. We get into a healthy stage in our lives, then things happen, life happens. We start putting our priorities in a different order. I know that I have. I have always put my kids first; however, I have decided that they don’t need me as much anymore and now it is time to start focusing on me again.

    I wish nothing but the best for you and remember, there are alot of us in the same boat as you. We can cheer each other on.

  6. DancingOpossum

    Re: weights. Not true, at least in my experience and observation.

    I started lifting weights as part of an overall bodily/health overhaul years ago. As it happens, I love lifting weights–it was, from the start, a delight to find some form of exercise that didn’t bore me to tears (like running), didn’t require mastery of ridiculous and pointless dance steps (like step), and was in fact enjoyable and mentally challenging. It also produced great results and gave me buckets of confidence.

    Unfortunately, my eating habits were horrible and I piled on yet more weight to the tune of 50 pounds. I began lifting more seriously, added cardio and a healthy eating plan, and lo and behold, I dropped 45 pounds in what seemed like record time.

    That was three years ago. Since then, I have managed to put it all back on, and more. Now I have those same 50 pounds to lose.

    What happened? I don’t know. My eating went straight to hell and my workouts became irregular, then stopped. I kept trying to get back into my groove and I just couldn’t for some reason. I don’t have a lot of tiem to spend psychoanalyzing myself, let’s just say that I got lazy.

    Anyhow, somehow I managed to crawl back to the gym and the weight bench: self-loathing, flabby and humiliated, but determined. A trainer who saw me return to the gym after months-long hiatus–and who had cheered on my progress when I was a regular–looked at me aghast and asked me where I’d been. I said, “The whole thing just fell apart.” His response: “Well, the main thing is that you’re back. A lot of people never make it back.”

    The good news is, my progress has actually been easier this time around–once I started. I got back on a lifting/cardio track and my diet is a hundred times better. I’ve started losing the weight again, slowly but steadily. Will this time be the final one? I can’t honestly say. I hope so, because I hated the way I felt when I put all that weight back on and went from hardbody to couch potato. Will that be enough to motivate me never to stop again? Again, I don’t know.

  7. Terri

    Congrats Amy! You must feel very proud of yourself. I’ve been struggling with my weight for 20 years. I took zenical, started excersing and lost 50 pounds. Then I got sick and stopped excersing and quit taking the zenical. The weight came back. Then I started regular 30 minute work outs on the treadmill, eating healthier and lost 20 pounds. Then I had some medical problems, double torn meniscus in both knees and stopped the treadmill. The weight came back and some. I’m 254 pounds, 5’3″ and I am disgusted with myself. When I read your success stories I so desire to be as committed. I am struggling to be strong. I’m embarrassed to go out with my husband because I feel ashamed that he has a fat wife. It’s so hard to imagine myself being 130 pounds. I am going to start again, eating healthy foods and staying away from man-made products. Because of my knees I am going to try aquasizing and go from there. I am giving myself a year and hope I can be where you are. Thanks for the inspiration!

  8. You On a Diet

    I think the most significant reasons for diets failure are wrong intentions and lack of preparation.

    What I mean by wrong intentions is going into a diet with a “quick fix” mentality. Being healthy is damn hard work until a routine and habit can be established.

    Lack of preparation is also a killer. If I didn’t have my meals prepared or thought out in advance I find myself settling for junk which can be a major setback.

    I really enjoyed the article. I’m researching the top reasons why diet fails and so far, I’m up to 16 reasons / excuses. Keep up the good work.

  9. XFactor Fitness

    I will tell you both from experience and through my profession, that diets do not work. It is a very very sad truth. I am a Personal fitness coach/trainer. I was morbidly obese at one point in my life weighing in at 240Ibls on a 5’1″ frame. I lost over 125Ibls and have kept it off for more than 7 years. The fact is, the only way to lose weight and keep it off is to change your lifestyle. You must have a combination of Cardio and resistence training, as well as a solid nutritional guideline. I can not stress how important it is to add resisiyance training, as well as cardio to your life.

    You must also learn what healthy eating is, and how it will change your life. In order to do that, an individual must understand that we are carb sensitive beings. In order to remove weight and maintain it off, you must understand what a good carb is, and what a bad carb is. The Atkins diet didn’t work because it removed all carbs, which is very dangerous, so they reinvented the diet, as our body needs a glucose to function. Most glucose is attained in natural carbs. This is fruits, veggies, and grains. In saying that an individual must also understand what are good fats and bad fats. Our bodies need fat to survive, but it needs certain types of fat. Some fats even assist in losing weight.

    What I am getting at, is I educate all my clients to understand what healthy eating is. Knowledge is power, and if you understand how our bodies function, it makes healthy eating and healthy weight loss very simple. This with a customized workout regimen, as not every workout regimen works for every person, are the keys to successful weight loss and more importantly it is the key to maintaining your ideal weight. I put out a free monthly newsletter to all my clients and anyone who wants some helpful tips, it also has some great recipe ideas. Feel free to go to my site and opt-in to receive it. It is under the fitness newsletter tab. I am very passionate about weight loss, as I remember all too clearly my struggles, and how badly I felt about myself. I don’t wish that feeling on anyone!!!!


  10. Jenelle

    This is a great entry. About 5 years ago I jumped on the low-carb wagon and lost an impressive 40 lbs in a relatively short amount of time. The success didn’t last long when I went back to eating “normal”, which was actually terrible. I gained all the weight back (and about 30 more on top of that!).

    About 11 months ago I started exercising regularly and eating healthy, whole foods. Lots of fruits, veggies and grains and found that I was missing out on all this GREAT food. I’ve since lost 100 lbs, and can only hope to keep it off by eating the food I actually enjoy eating.