It's Science: Diets Don't Work

Hey, guess what? Diets don’t work. Researchers who recently completed the biggest ever study of diets and dieting have concluded that you’re better off not bothering. From Independent:

“Diets do not lead to sustained weight loss or health benefits for the majority of people.”

Researchers analysed 31 long-term studies that followed participants for two to five years.

“We concluded most of them would have been better off not going on the diet at all. Their weight would have been pretty much the same, and their bodies would not suffer the wear and tear of losing weight and gaining it all back.”

[UCLA associate professor of psychology Traci Mann] added: “My mother has been on diets and says what we are saying is obvious.”

So what does work? Exercise. But you already knew that, didn’t you? —MEGHANN MARCO

Most dieters ‘end up heavier’ [Independent]
(Photo: Beige Alert)


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  1. Nick says:

    …and the lesson is, never try.

    Most people don’t stick with diets and do gain the weight back. But if you’re an overweight fast-food eating milkshake-drinking person, you should absolutely go on a diet. Diets work quite well if you stick with them. The real message here should be “abandoning your diet is more harmful than never going on one in the first place.”

  2. royal72 says:

    @schwnj: “Diets work quite well if you stick with them.”

    hey captain obtuse, that’s exactly what the research says, people don’t, won’t, and cannot stick with them! ie: diets don’t work.

  3. r81984 says:

    Diets never work if you go back to your old eating habits.

    Its the bad eating habits that made you overweight, so if you lose 50 pounds and revert you will gain weight back.

    To be successful you cannot diet, but you have to change your eating habits for the rest of your life.

  4. WhatThe... says:

    Ditto what r81954 said. It’s not the diets that work, it’s changing the bad eating habits. Start small and work on one thing at a time. My first goal – limit eating out to once a week maximum! Now down to once every two weeks. Switched from 2% to 1% milk – lose some fat and calories there. Now working in more fresh fruit and veggies.

    No, that’s not drastic weight loss results, but I feel better and not weighed down.

  5. DeeJayQueue says:

    It’s not about saying “oooh i have to eat low carb” or “I can only eat bean sprouts and pita bread” because all those restrictive diets do is make you want what you can’t have. You have to realize that you’re putting crap into your body and make a complete change in the way you think about food. Yes it tastes good but that’s not the point. Food’s point is to provide fuel and nutrition for the body. People need to stop relying on food as a crutch for depression, stop treating it as a legal high, or a cheap pleasure device, and start treating it as simple nourishment. Make things that are healthy first and taste good second. This is not impossible, in fact it’s really easy, but it’s nothing at all like eating Wendy’s every day.

    The other key factor is exercise. you have to be willing to commit to some sort of regular exercise, even if it’s just to join a bowling league or walk a couple miles on lunch or whatever… do something. the more you do you’ll find the more you want to do, and pretty soon you’ll notice changes, changes that will make you happy and realize that it’s working. Meanwhile as your body changes, your lifestyle changes. You get used to eating chicken without the breading and cheese and fat. You get used to running or riding a bike to the store instead of driving. After a few months of doing this it becomes routine, and not only will you lose weight, you’ll gain muscle mass and tone, look and feel better, have more energy and just sorta glow.

    How do I know this? Because I’m in the middle of doing it, for the second time. I was overweight, changed my diet and started exercizing. Lost 20 lbs, but then lost all my discipline when i got into a relationship. Gained it all back, plus an extra 50. I’ve lost 30 of that again, back to the same eat less and exercise routine, and it’s working.

    Having a good support system of friends and relatives helps too. It’s good to find someone who wants to change for the better at the same time you do, to help curb some of the cravings and to keep discipline and focus.

  6. rixatrix says:

    What we’re still lacking is a clear definition of what “diet” defines. Does it mean cutting calories, modifying my eating in a drastic way, cutting out food groups, forcing myself to adhere to unrealistic rules such as only eating three times a day, etc?

    Without the definition of “diet”, the lines between successful weight loss and failure are blurred.

    Any kind of weight loss generally requires me to rethink the food I’m putting into my body. Whether the changes I make are sustainable or not determine wither or not my “diet” is successful. For instance, if I love fruit and I vow to go on Atkins, eventually I’m going to miss aspects of my old diet and slip up. If I modify my eating to include more protein along with the things I enjoy, I’m much more likely to stick with my new eating plan. Which one is considered a diet? Are they both?

    It’s old news that exercise enables weight loss, but without good nutrition in place, it’s like fighting a losing battle. Weight loss results come from the marriage of good nutrition and exercise.

    To suggest, even broadly, that most people are better off without any sort of healthy changes to their day-to-day diet is just absurd, and enables the American public to continue eating unhealthy foods while saying, “See? I told you there’s no point in changing.”

  7. SOhp101 says:

    Diets don’t work, changing eating habits does.

  8. Hedgy2136 says:

    Over the past 20 years, I managed to pack on about 70 pounds. Three months ago, I finally got fed up with it and began a walking program. I started out modestly (about 2 miles a day), and now am up to 10 miles per day. I have lost 30 pounds in the past 12 weeks without changing my eating and other lifestyle habits at all. It is simple, if you burn more calories than you consume, you will lose weight.

  9. Hedgy2136 says:

    @ SOhp101

    If you live a sedentary lifestyle, even if you don’t consume too much, the only way to lose weight is to get up and move around.

  10. skittlbrau says:

    agreed – some diets are absolutely unsustainable in the long run.

    that being said, something that gets you to fundamentally change your eating habits – weight watchers is good for this. eat veggies, fruits and other healthy items in moderation is a big tenet of the plan. my mom lost 100 pounds this way and hasn’t gained a pound back, and its been 7 years!

  11. [UCLA associate professor of psychology Traci Mann] added: “My mother has been on diets and says what we are saying is obvious.”

    Of course it’s obvious! How much money did they spend on this?

  12. oldhat says:

    The famous Meth Diet has the same problems…strangely, people can’t seem to stay on it for very long. At first, it’s great, you loose everything, even your teeth, but then people get lazy and start sleeping and eating again. Usually in jail.

  13. jurgis says:

    @baa: Exercise is the only thing that will really work. Going on a diet is fundamentally different from just eating more healthy. You shouldn’t consider that a “diet” (using the common definition) as much you should actually have a healthy diet.

    For instance, I became vegetarian a year ago and I eat much more healthy foods, but it’s not a “diet” in the sense of trying to lose weight (although I have).

    I run to lose weight ;)

  14. aiken says:

    In other news, it’s pointless for students to play sports at school, since the majority of them will never make the major leagues. This instillation of false hopes and dreams can only do harm.

    And those of you in bands? Give it up. The majority of you will never go anywhere. If you keep it up, you’ll be worse off because of the disappointment.

    And, ultimately, there’s no point in getting out of bed in the morning. You’re going to die eventually. The extra stress of going to work and interacting with family can really only make things worse.

    What a load of headline-seeking crap. Sure, diets may not work for *most* people. Doesn’t mean they won’t work for you, if you need it and are motivated to actually change your life and habits. Most people aren’t; that’s not news. Saying that people shouldn’t try is an amazingly obtuse conclusion to draw from this data.

  15. cgmaetc says:

    hey captain obtuse, that’s exactly what the research says, people don’t, won’t, and cannot stick with them! ie: diets don’t work.

    So.. something is deemed not to work because people don’t use it right? That’s like saying cars don’t work because people crash them!

  16. dandyrandy says:

    1 peanut butter sandwich = 300 calories
    1 hour bicycling = 300 calories

    Is an hour of your time worth a peanut butter sandwich?

    Exercise doesn’t work either. The ONLY thing that works is eating less than you burn.

  17. CumaeanSibyl says:

    “Diets” work exactly as advertised. The study even says that, right out — if you go on a diet, you’ll lose weight. As far as long-term results, though, most diet plans you’ll find aren’t worth the money or the deprivation, because they will not teach you how to keep the weight off. They’re meant as a short-term weight-loss program, and that’s all they do.

    So no, it’s not “because people don’t use it right” — it’s because they’re not designed for long-term results. And nobody’s saying that “people shouldn’t try” — we’re just saying that, if you want to lose weight and keep it off, “diets” are not the answer.

  18. aiken says:


    I’m not sure which “we” you’re referring to, but the quoted portion of the original article says “We concluded most of them would have been better off not going on the diet at all.” Which, the way I see it, means they shouldn’t have tried.

    And I think the issue that I have with that wording, and with your post, is that it’s a terribly black and white way of looking at things. Just because the majority of people who try diets find that any weight loss is short-term, it doesn’t mean that nobody ever benefits from diets and that therefore people shouldn’t use them.

    Diets aren’t the *whole* answer, of course. But to suggest that they do more harm than good and that people, in general, would be better off not using them (as the original article concludes) is just shock value and an almost nihilistic idea that isn’t supported by the data.

  19. higginsrj says:

    I went on a “diet” consisting of chicken and fish, vegetables, grains, nuts and fruit — avoiding sugars, white flour, etc. Lost 30 pounds. That was three years ago, and my weight is the same.

    Clearly, that qualifies as a diet. But it’s a sensible, straightforward diet, that really is not hard to stick to. Eventually this “diet” became my regular eating habits.

    So… perhaps what they really mean to stay is “restrictive diets don’t work.” Which, of course, we already knew.

  20. kimsama says:

    @dandyrandy: Actually, by exercising, you build muscle, which increases the number of calories your body needs in a day (even when you’re not moving, or when you’re sleeping). Each pound of muscle you add burns like 30 extra calories a day, even if you do nothing.

    So exercise is win-win: you burn calories when you do it, and you keep burning them so long as you build some muscle.

  21. asherchang says:

    It’s say that diets don’t work by themselves in the long run (although for some reasons, they’re not as effective w/out excercise in the short run, either). However, excercise by itself won’t ensure weight loss, as I’ve learned this year after I’ve gained 20 lbs, at least 12 of which are sure to be fat.

    And a quick factoid: swimming uses alot of energy, but the water cools you down, taking away the apetite-supressing ability of the exercize, making you sometimes eat more Calories than you lost.

  22. Mr. Gunn says:

    Gee, if you define a diet as “that which causes temporary, non-lasting weight loss” then it’s not surprising that you don’t find that they work long-term. Taking as your assumption that people won’t learn from them and retain healthy eating habits is setting your study up for failure.

    I think these researchers just wanted a little face on Oprah, personally.

  23. royal72 says:

    @cgmaetc: “So.. something is deemed not to work because people don’t use it right? That’s like saying cars don’t work because people crash them!”

    sorry, maybe my comment was a bit too brief… people are stupid.

    we don’t think for ourselves, we don’t listen to our own bodies, and pretty much take things “as advertised”. doctors don’t know shit on a general scale. they flip flop on what’s good for us constantly. ie: drink a crap load of water a day… err, wait, now you’re flushing all the minerals out of your body. don’t eat eggs, oh wait, eggs are ok. too much red meat, actually go ahead ’cause it has lots protein and other good stuff.

    we just don’t have a fucking clue, because it’s always from one extreme to the other. it’s all bullshit. the simple answer is, take a few week to experiment with your food intake. what foods make you feel energetic and how much. what do you eat at what time of day?… and speaking of “cars” in your reply, food is fuel for you body, use it accordingly. people crash their bodies everyday, by yo-yo-ing (is that a real word?) and that is the point of the study.

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  25. Elle Rayne says:

    Neither do diet pills.