Why diets don’t work: the talk

Sandra Aamodt giving TEDGlobal talkWelcome, TED viewers! My talk from TEDGlobal in June 2013 was posted today. For those who came here looking for the details, I’ve got you covered. Start with the three posts explaining the science behind the talk: Weight and health – show me the data!, Long-term effects of dieting, and Early dieting predicts weight gain. Then move on the my favorite post on the site, How obesity is like nearsightedness, which explains how genes and environment interact to control body weight.

These ideas didn’t originate with me, of course. This research represents decades of work by many scientists, much of it old enough to be found in physiology textbooks. But since most people don’t read textbooks, here are some good places to look for more information.

The Health at Every Size community site has many resources for people interested in focusing on healthy behaviors without dieting, including the Fat Friendly Health Professionals list.

Much of the work on fitness versus fatness comes from Steven Blair of the University of South Carolina. Here’s an interview containing his recommendations for a healthy life. Just 30 minutes a day of moderate exercise is enough to provide most of the benefits.

The Fat Nutritionist has a good recent round-up of the science on why people have a strong tendency to regain the weight lost by dieting.

Arya Sharma is an obesity specialist who takes a realistic view of the difficulties associated with weight loss. Most relevant to my talk, see his blog posts Will losing weight make you fat? and Will losing weight make you sick? [links to his site are failing intermittently, but they're correct]

Here’s a nice summary of the original study by Rudy Leibel, Jules Hirsch and colleagues showing that weight loss reduces metabolism.

If I’ve missed anything that you wanted to know about, tell me in the comments, and I’ll update the post later on.

46 thoughts on “Why diets don’t work: the talk

  1. One of the questions I’ve wondered about is the role of exercise in shifting a high setpoint downwards. On the one hand, some levels and/or types of exercise can drive appetite, so that’s not ideal. On the other, it’d seem plausible that carrying around lots of excess fat would interfere with hunting and gathering, so some of the right kind of movement might encourage the brain to give up unnecessary stores. I wonder if this might work particularly well if done while (mindfully) eating a nutrient-dense diet, i.e., that is to avoid tripping any of the starvation mechanisms.

    • Beth, the research so far suggests that the hypothalamus increases hunger to compensate for calories burned during exercise, with astonishing precision (see http://nymag.com/news/sports/38001 for more details). But I’d love to see the effort that we’re currently putting into studies of various diets go instead toward some new ideas. Whoever finds a reliable, non-invasive way of shifting the set point downward is going to be exceedingly rich!

    • I am an exercise enthusiast, go to the same gym since 2001, and I observed many people who are getting fatter while exercising intensively year after year. Fat Zumba instructors are far from being rare . Having extra fat doesn’t seem to interfere much with people’s ability to move well and fast, however weight affects speed and the susceptibility to sport injuries . In my case low-carbing since 2007 eliminated excessive appetite and allowed me to keep off my lost 30 lb.

  2. Thank you so much!!! I have been saying this for about a year now but didn’t have the creds to back it up. Although I am a nurse practitioner, I didn’t know how to clearly state this concept of Mindful Eating. I’ll be sharing this talk in my blog today. I’ve been eating mindfully since August and have lost from 256 pounds to 232 without denying myself the foods I love to eat and without sweating an awful lot. I eat exactly as Sandra Aamodt describes: Only when I am hungry, only until I am not hungry, more fruits and vegetables, fewer carbohydrates, I don’t smoke, I exercise enough to have my heart rate up a little almost every day and use alcohol only two or three times weekly. I wish I had given up on the diet craziness and done this years ago. Thanks!!!!

  3. I wish someone had shown me that video when I was 13 too. I’m 45 now and most of my life Ive had issues with food. I learned how to count calories when I was a small child watching my mother go to endless weight watchers meetings and I decided I was fat when the school nurse weighed me in at 8st (I was 5ft 5”). I gave myself extra crispbreads if I swum extra lengths in training. Looking back it was hard and part of it was down to the medication I was on for epilepsy. Sandra Aamodt talk was absolutely fascinating and listening it would have spared me years of problems with bulimia and controlling eating however in 2010 my medication was changed, from what I gather it has some effect on the hypothalamus too and the first question I get from neurologists and doctors isnt ‘when was your last seizure?’ its ‘ are you eating?’. I dont much care what I eat any more and tend to have to be reminded to have meals. It has been very much a case of be careful what you wish for. A while back I went back to a combination of my original medication and the new one in the hope of putting some weight on – or at least feeling hungry; no luck. It looks like something else Sandra Aamodt said in her TED talk is correct my ‘weight’ is now a full 20lbs down from what it has been most of my adult life. I’ll always have this, maybe when I’m in my 80’s they will find a drug that means I will start to enjoy food again and feeling hungry. At the moment I’m controlled, 16 months seizure free, its a price you pay for that control.

  4. MIndful eating…I’ve been trying for years and I can’t figure out how to do it. I joined the ‘clean plate club’ very early in life and I’m really really bad now at stopping when I’m full. I always just want one (or three (or ten)) more bite(s) if it tastes good. This or that extra doesn’t seem like a big deal unless I’m weighing/measuring/tracking what I eat and then I can make rational decisions based on the numbers (most of the time).

    I’m concerned now about how this is going to affect my children. Right now they think it is weird that I weigh my food and they’ll walk away from anything (even chips) when they are full. But how long will that last when I can’t model the same behavior? Is it bad that our culture constantly uses food as a reward? How does that affect them?

    Are any of these good?
    http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=mindful+eating

  5. Oh my, what a fantastic TEDtalk! I am 58 years of age and have dieted for the last 46 years, constantly swinging between the joy of slimness and shame of weight gain. Mental anguish has been my companion for the majority of those long years of wasted energy. I, too, wish that I had never dieted. Thank-you for freeing me at last, Susan, with your liberating and sage advice. Importantly, those four salient points are do-able: eat lots of fruit and veg, exercise 30 mins x 5 times a week, don’t smoke (gave up 12 years ago), and drink moderately (I only have 3 to 4 glasses of wine a week). Exercise has been my sticking point, but with the other 3 items in the bag, I need only concentrate on this one thing, instead of feeling overwhelmed by having to struggle with restriction, hunger, guilt and stress.

    • That same New Year, at the beginning of 2010, I resolved to walk for 30 minutes every day. I’d tried to build that habit many times before, but concentrating on just one change made the difference. I’ve walked almost every day since then.

  6. Thanks for your great and inspiring TED Talk, Sandra. I have read a lot of the links here on your site, and lot of other literature and websites since embarking on a lifestyle change almost 2 years ago. I now have a personal trainer and follow a healthy eating plan designed to help me eat the correct amounts of all the major food groups, it seems to be a more sustainable way of losing weight, at least for me. My trainer focuses on strength and building muscle to change body composition and increase fitness rather than exercising to lose weight. The literature and links here don’t mention the effect of increasing muscle mass, they only refer to exercising and dieting to lose weight. I know dieting alone can lead to loss of muscle mass and that shift can affect some of the side effects mentioned in the links – even thought I realise it’s not that simple. Do you have statistics relating to loss of body fat and keeping it off when taking this kind of approach?
    Thanks again, I look forward to all your future posts!

  7. What a wonderful and inspiring TED Talk. This is thirteen minutes I believe can change a life.

    As a pediatrician that founded and online child wellness and weight management program, we spend so much time teaching parents about the risks of dieting and the (lifelong) benefits of mindful eating. On the Healthy Kids Weight Management and Wellness Program children learn to listen to their internal satiety signals; dieting is never recommended.

    This talk teaches so much in a short time that I will recommend all our parents view it! Thank you.

    Jennifer A. Gardner, MD, FAAP, Founder, Healthy Kids Company http://www.healthykidscompany.com

    • You’re right that body weight is strongly influenced by genes. In our current environment, weight is as heritable as height. Researchers have even identified a particular gene deletion that increases hunger and decreases metabolism. But weight is also strongly influenced by the environment, as I explained here. We can see that from first principles – it’s hard to gain too much weight if finding food requires a lot of exercise. Personally, I think it’s likely to be easier to change our environment than our physiology.

  8. Sandra, thank you so much for spreading the word, I have believed for many years that our minds have complete control over our bodies and our weight, and that diets do not work in the long run, so I am extremely happy to see so much science emerging that supports this.
    But I have to disagree with your comment about the difficulty in decreasing setpoints and would like to share my story with you- it IS possible to decrease it as I myself have managed this thanks to a lot of reading and understanding what was going on in my mind. I was aged 18 when I went on my first diet, as I was obese and 60 pounds heavier than what I believe my body’s natural set point should be, but after a lot of restrictions and battles of will power I only lost around 14 pounds, which I put back on again once I stopped the diet. Over the following year I read A LOT, and found that the environments I had been in and the stresses I had experienced in my life had been what had shifted my set point up as I got older, and as soon as I addressed these stresses and dealt with them, I was able to lose weight and stay at the lowered weight, as I learned my brain and body were simply reacting to these stresses as if I were in a famine, which, as you said, is how it reacts when we diet.
    I dealt with one of these problems/residual stresses, and I lost 20 pounds, and kept it off for 2 years (regardless of the fact that I started university where I ate unhealthily and increased my alcohol intake substantially). I then spent a summer dealing with another issue that was causing/had caused me and my body a lot of stress (in combination with learning more about nutrition and exercise) and lost another 20 pounds, which again I have kept off for a year and a half, even though I ate whatever I wanted and only exercised 3 times a week (when I wanted to) and again my weight has hardly fluctuated since.
    I am currently in the process of addressing the final issue (a deep rooted problem which I have quite literally held onto since early childhood) which I know now is what is causing me to hold on to the final 20 pounds. But what matters is I no longer look overweight, am the healthiest I have ever been and perhaps most importantly, I have still managed to decrease my set point gradually and keep it low by addressing the environmental factors/stresses that caused the increases in these set points in the first place, just as you addressed yours (dieting).
    And I am not the only one, one man in particular, Jon Gabriel, has been the biggest inspiration to my weight loss journey, and I think your research would benefit hugely if you read his work, because like you, he too only lost weight as soon as he stopped dieting for good (although he had been chronically dieting much at a stressful point in his life that his setpoint shifted upwards far more than yours).

    What is your opinion about this? I would love to hear your thoughts.
    -M

    • Resolving emotional issues can lead to long-term sustainable weight loss in some people, presumably because the higher weight was above that person’s set point. For some lucky people, set points take a long time to adjust upward, even when overeating is sustained. For others, it happens more quickly. I’m glad it worked out well for you!

  9. It would be interesting to know if there is any knowledge on the role of fasting on the set-point. Since taking up intermittent fasting, my satiation point seems to have shifted dramatically. Even on non-fasting days I feel nowhere as hungry as I used to, with obviously positive results.

    I hear the same thing reported by others, some of which is posted here: https://medium.com/body-2-0

    • We don’t know yet. There are only a small number of long-term (over 2 years) studies of any diet, and intermittent fasting is a fairly recent idea. Here‘s a year-old round-up of the evidence. I’ve heard some anecdotes about people who do feel hungry on that diet, including a quote from Mark Mattson, one of the leading scientific proponents of the idea. But a key takeaway from all the diet research is that you shouldn’t start any eating plan that you can’t stick to forever, so congratulations on finding something that’s working for you.

  10. A quick search on the web, after seeing your TED video, and I came accross this:
    http://www.bidmc.org/YourHealth/BIDMCInteractive/Break-Through-Your-Set-Point/Week-One-The-Science-of-Set-Point.aspx

    They claim that if you lose 10% of body weight and then keep it off for 6 months, it will lower your set-point – then you repeat it again and again.
    Perhaps you can ask them for their evidence and evaluate it for us?

    Also, there’s an artical here: http://jn.nutrition.org/content/127/9/1875S.long
    which indicates evidence that Fenfluramine lowers the set-point a certain amount.

    • Many drugs seem to influence the set point, usually only for as long as you keep taking them. Nicotine tends to reduce weight, and so does fenfluramine, though not by as much as researchers originally hoped. Doctors don’t recommend either of them these days, since smoking or heart complications from fenfluramine can kill you. Antidepressants and many other common drugs often lead to weight gain, which may have caused some part of the recent rise in obesity.

      Thanks for the link claiming that people can lower their set points by losing weight slowly. I’d love to know what evidence that’s based on, if any. A recent review in the New England Journal of Medicine concluded that the rate of weight loss had no effect on long-term success.

  11. Interesting ted talk!

    But i have a question on my mind that im sure every other man have on his mind too..

    so if you got a set point of wheigth lets say i am set to whey 85kg.
    I whey around that now. But i have abaout 10% bodyfat i want delete.
    The best way to do this is gain more muscle, and then automatic will the body try to burn the fat ro keep me on the 85kg. Will it work or are the set point a point that need you to habe 15% bodyfat at the kg of 85?

    Let me ask it at a differebt aproach.
    Is it easier to try to gain muscle to to your set point of 85kg to be happy naked in the mirror. Than try to lose those 10% fat, and be below set point, that you need to look good naked..

  12. Hi there,

    I have been watching your very interesting talk (going to talk about it on my website, but, alas in Italian :D ).
    One thing I didn’t understand: looking at your graph, why is it that people with normal weight and 0 “good” habits have a reduced “relative risk of death” compared to those with only 1 “good” habit?

    TIA

    • That small difference is probably just random variation in that particular study. I wouldn’t take it too seriously.

      • Hi there, thanks for the reply, although I would have felt happier if you had said it was a misprint, a typo or such like… Not having seen the raw data (and not having any intention to do so :) ), how do I, or my readers, know whether the rest of the graph is equally insignificant?

  13. Thank you for this talk, Sandra. I am interested in the information about factors that predict weight gain and eating disorders five years down the road (found at about 7 minutes into it). Early dieting was the one you were focusing on, and the other — family teasing — was just a mention. I was overweight from childhood (according to mom) am now obese, and the teasing was ever-present. Not looking to blame, but to understand and hopefully heal, I would appreciate learning more about that, and any other factors that may be included with these two. Can you direct me?

  14. Hi, I loved your TED talk. I do have one question. At the end you state “I’m talking about mindful eating: learning to understand your body’s signals so that you eat when you’re hungry and stop when you’re full, because a lot of weight gain boils down to eating when you’re not hungry.”

    And then a bit further on you mention “I should say that this approach to eating probably won’t make you lose weight unless you often eat when you’re not hungry [...]“.

    Could you explain that to me? As I understand it, (please correct me if I’m wrong) you say: “stop eating when your hunger is over, but even better, eat before you are hungry in order never to get hungry, as hinger increases risk of overeating”

    Anxious to get your reply, many thanks,

    Guillaume (Amsterdam, The Netherlands)

  15. Hi Guillaume – what she meant when she said “eating probably won’t make you lose weight unless you often eat when you’re not hungry”, is that losing weight by the method of Only Eating When You Are Hungry – And Stop Eating When You Are Full, will only make you lose weight if you were the type of person who had first become fat by often Eating When You Are Not Hungry (eating for comfort). But if you became fat for another reason (i.e. because of medication or hormone imbalance) then this method of dieting might not work.
    So all you have to do, is listen to your body and decide if you really feel hungry (then you eat) or if you just have a desire for food for a different reason (then you don’t eat).

  16. Hi Jarrick, thanks for your comment. But how does an overweight person understand the difference between hunger and hunger? I’m not a neurologist, but I imagine the signals for ‘real hunger’ and ‘comfort hunger’ are similar… Certainly when you take into account that a lot of overweight persons have a faded or delayed satiety response, which makes it harder to understand when to stop.
    That would still imply your cognitive brain to overrule your autonomous brain, which is willpower, which is limited.

  17. I don’t know about everyone else, but personally I find that the feeling of propper hunger comes from the stomach, whereas eating just because you desire food comes from the mind. A good way to feel the real feeling of hunger is to stop eating for a day (and just drink plain water) – at some point you should get a feeling in your stomach. Another thing, is to try and recognise if you are hungry for food or just thirsty – for me I used to confuse the feelings and eat food when I was really just needing liquid.
    The other problem with people that over-eat is that they may have a distended (over stretched) stomach and they won’t stop eating until they get a feeling that their stomach is bursting – and so they eat too much. Sometimes people confuse the feeling of being over full with the feeling of hunger and cary on eating even when they’re bursting. One way to try and correct this problem is to eat no more than 1 litre volume of food at a time – get a measuring jug, fill it to a litre with something like peas, beans, sweetcorn etc.. and tip it on your plate. That will give you an idea of how much is the maximum the average stomach should hold. Once you’ve eaten – wait for an hour and check to see if you’re still hungry before you eat any more. It’s better to have 4 or 5 small meals a day than one gigantic one.
    Ultimately, none of this is going to work without will-power or a strong desire to change. you might be able to tell the difference between real hunger and comfort eating but without will-power you won’t make any changes. And the only way to gain more will power, is to exercise it – take control.

  18. Hi Sandra, how are you? I’m journalist from Harper’s Bazaar Brazil and I’m doing a story about your study for TedGlobal. I really want to talk with you about this, please. Is there an email or a contact that we be able to talk? If you want, can contact me in my email: julia_tiberio@hotmail.com.
    Thank you for your attention and congratulations for your job.
    Best,
    Julia

  19. I loved the talk you did just like many people around the world. I decided to go on a diet about 2 years a go by joining a local Crossfit gym and getting on the paleo diet. I worked out at crossfit for two days a week for one hour per session, intensively. I was on the paleo diet in the strictest most way. I must say I lost 30 lbs in the first 4 months. I then had to stop going to the gym for various reasons and sure enough after about 3 months or so, I was back where I started 190lbs.

    I will start again but this time I will use methods which don’t involve “diets” or the gym. Simple, effective everyday methods that are sustainable and work. I’ll provide full documentation of how I did it and the results I got on my blog. Again thank you for the inspiration.

  20. Dieting doesn’t work. Exercise doesn’t work so what does work?
    I am over weight by at least 60k take three blood pressure tablets daily and I am thoroughly confused by all the contradictory advice relating to healthy weight.loss.
    My GP tells me the weight I carry around my stomach is as bad as smoking and it needs to shrink otherwise I am in line for diabetes and other weight related issues.

    So whats the answer?

    i am 55 and totally frustrated about weight loss!

    • Exercise typically doesn’t lead to lasting weight loss, but it can reduce abdominal fat and its health consequences, even when total body weight remains the same. Don’t give up on the gym just yet!

  21. Is there any data on the correlation of Quitting smoking and a raised set point? My personal experiences mimic what your presentation demonstrates. But you only talked about weight gain as a result of dieting. The only times in my life when I changed my body weight was when I quit smoking. I was at an ideal 18-20% body fat my entire life unitl I quit smoking. I gained so much weight so quickly I didn’t even have underpants that fit. Then the gain stopped after a few weeks and didn’t budge for the two years I remained a non-smoker. To make matters worse life got in the way, I started smoking again but with no change in my weight. I quit after a few months and again I gained weight that remained constant through the cycle of two years of non-smoking and then several month of smoking and didn’t budge until I quit. This cycle repeated five times unit I managed to stay a non-smoker for eight years. However happy I am that I am a non-smoker is diminished by the 80 pounds over weight from my efforts. I remain a non-smoker because of the idea that I will gain more weight when things improve. I don’t think I can emotionally handle a BMI above 35.

    • Smoking is one of the few known ways to lower the weight set point, although your experience of repeated cycles is unusual. Most people weigh 8-10 pounds less when they’re smoking than when they’re not. Obviously, though, the health risks of smoking are much worse than the weight gain associated with quitting.

  22. Sandra- what a wonderful and powerful speech. Thank you thank you thank you! It actually brought tears to my eyes. I am 54 years old, have been a fitness instructor all my adult life, I am very strong, very flexible, and have above average cardiovascular capacity. However I have always been or felt a little overweight. I have dieted all my life and as of this morning decided I was tired of that roller coaster lifestyle and was going to stop worrying about my weight. Then miraculously this afternoon I saw a video of your speech tweeted from Shape magazine. It was exactly what I needed to hear. Great job!!

  23. Do any of these studies define dieting? Does dieting refer to calorie restriction only as opposed to dietary changes without a reduction in calories?

    • For the physiological responses that I discuss in my talk, dieting refers to intentionally losing weight below your set point by any means. The metabolic changes are a result of substantial weight loss itself (typically more than 20 pounds, though that varies across individuals), and it doesn’t seem to matter exactly how the weight is lost – low-fat, low-carb, starvation, slowly, quickly, whatever.

  24. Sandra I have posted your great TED talk to my Mindful Slimmers facebook and twitter accounts. As a mind coach and clinical hypnotherapist I have long encouraged my weight loss clients to reach a healthy weight using mindful eating techniques – including awareness of body signals, emotional triggers and external prompts to eat when not hungry – to change the way they think, feel and behave around food.
    This perfectly encapsulates the approach ‘Don’t diet, eat mindfully’
    Thanks!

  25. Hi Sandra
    Have you done any studies on the effects of heavy weight training & body re-composition with regards to set point? From my experience, while my set point (weight) will stay the same, my body composition will change (more muscle, less fat).
    Thanks
    Lauren

    • The set point refers to the amount of fat. Muscle mass can undergo lasting change when you modify your lifestyle.

  26. The main point Sandra is making is to learn to listen to your body, as to whether you’re actually hungry or not, in order to keep your weight at what it should naturally be – but I think there is another side to it;
    If you look at children, they are constantly fidgeting and stretching and moving about. Like hunger, but more subtle, there is a feeling or desire to move – which makes sense because movement is absolutely necessary for our bodies to function correctly.
    For whatever reason, a lot of people lose touch with this desire and become sedentry, yet they still want to eat the same amount.
    So, I think that if you are learning to listen to what your body needs, then these two aspects would compliment each other.

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