Do positive fantasies prevent dieters from losing weight?

Want to WOOP yourself into amazing shape, and fulfill your wildest dreams? Then get a self-help book telling you how through the Association for Psychological Science or the British Psychological Society Division of Health Psychology…Well not really, save your money.

I was like woopIn this issue of Mind the Brain, I discuss my tracking back into the scientific literature claims about positive fantasies and weight loss made for a self-help book promoted as science-based. I locate the study in which the claims supposedly arose. I find no basis for misleading and highly unrealistic claims. Rather than disseminating any science of positive psychology, the marketing effort for the book promotes unrealistic assumptions about what can be accomplished by dieters trying to lose weight. People who take these claims seriously can be demoralized by unrealistic expectations and encouraged to blame themselves when they can’t achieve what is presented as so simple. This promotion holds out the unwarranted promise that if people want to lose weight, they just need to buy this book, and integrate its simple exercises into their everyday life. If they have failed in the past, they can now succeed. Dieters are being exploited and made to feel bad.

Rethinking Positive Psychology  and an associated WOOP app were highlighted in a featured book signing at the annual convention of Association for Psychological Science. If you missed that opportunity, you still get to a site promoting the book through links at advertisements for the British Psychological Society Division of Health Psychology Annual Meeting.

The book/app package is organized around a simplistic idea. From the book’s preface:

Rethinking Positive Thinking presents scientific research suggesting that starry eyed dreaming isn’t all it’s cracked up to be. The book then examines and documents the power of a deceptively simple task: juxtaposing our dreams with the obstacles that prevent their attainment. I delve into why such mental contrasting works, particularly available via subconscious minds, and introduce specific planning process that renders even more effective. In the book’s last two chapters, apply the method of mental contrasting 23 areas of personal change – becoming healthier, nurturing better relationships, and performing better at school and work – I offer advice on how to get started with the method in your own life. In particular, I present a four step procedure based on mental contrasting called WOOP – Wish, Outcome, Obstacle, Plan – that is need to learn, easy to apply to short-and long-term wishes, and is scientifically shown to help you become more energized and directed.

From the outset, the author tries to convince us that positive thinking or, more precisely, positive fantasies by themselves lead to negative outcomes. The research that is cited is almost entirely the author’s own and often consists of contrived laboratory studies with weak findings. A large body of null and contradictory findings from others is shoved aside. This is not about translating scientific findings into practical life strategies, it’s about selling a self-help product as more sciencey than the rest. Buyers beware.

Like me, you probably figure from everyday life experience, that positive fantasies are rather harmless (*) Asked the question, “Are positive fantasies good or bad, helpful or destructive?” we would probably answer “It depends.” By themselves, positive fantasies can have little or no effect, and when they do, effects can be positive or negative.

wOOP i got chicken soupCertainly we don’t want to get caught up in unrealistic fantasies, but who does succumb to them? Maybe you get suckered, if you have been taken in by Chicken Soup for the Soul or a Tony Robbins seminar and think that you can dream yourself to health and wealth. Of course, it helps to be realistic and have a workable plan, but we don’t need a self-help book to tell us that. This book provides very little useful advice about how we should cope with the obstacles we encounter.

Way back when I was in graduate school, there was a lot of excitement about using positive fantasies elicited from people as a way of predicting achievement motivation. Interest in the idea waned when it was shown that such assessments were generally unreliable. Any predictive value disappeared when IQ or productivity was taken into account. Keep that in mind as you read on: why should we think that fantasies elicited in contrived exercises should have much predictive value about things off in the future and subject to lots of other influences? Why would we presume that a fantasy elicited at the beginning of a weight loss program would predict what was actually lost a year later?

But the author is selling a book making a strong case that having positive fantasies are destructive of getting your goals achieved. An impressive publicity campaign hit major media outlets with a mind-numbing repetition of the same message. You could find it in pretty much the same thing being said in the Wall Street Journal, USA Today, the New York Times Sunday Magazine, the New Yorker, The Guardian, the Atlantic, Psychology Today, Huff Post, etc. etc.

le woopThere were also impressive endorsements from celebrity positive psychology gurus. Like the media coverage, these endorsements had a certain sameness suggesting the endorsers  were coached, if not outright provided with a script. Typical of these endorsements, Angela Duckworth, the author’s labmate and sometimes co-author back in Seligman’s lab gushed:

I was once asked by educators to identify the single most effective intervention for improving self-control. Every scientist I spoke to referred me to the work summarized here – masterfully in with incompatible insight and warmth. Read this brilliant book and then go out and do what Gabriele Oettingen recommends. No changes the way you think about making your dreams come true.”

I wanted to track some wild claims in the book and promotion back into the scientific literature and see if they held up. A recurring claim about weight loss triggered my skepticism.

In USA Today: Positive thinking? It’s not enough to reach your goals


One of Oettingen’s earliest studies showed that positive thinking alone can backfire when it comes to losing weight. In that study, women in a one-year weight loss program who had the most positive fantasies about future slimness lost an average of 24 pounds less than women with less rosy visions.

In the Wall Street Journal: The Case Against Positive Thinking

In one of Dr. Oettingen’s studies, obese participants who fantasized about successfully losing weight lost 24 pounds less than those who refrained from doing so.

A difference of 24 pounds in a weight loss program is huge. Consult a 2015 meta-analysis  of weight loss in self-help programs. You will see that at six months participants in weight loss programs are typically better off than those in the control condition by only 1.85 kg or 4.78 pounds. At 12 months, any benefit of being in the self-help program has disappeared.

Another meta-analysis evaluated commercial weight-loss programs like Weight Watchers, Jenny Craig, and Nutrisystem. Available evidence was limited and of poor quality, plagued by short follow-up periods of generally less than a year, high dropout rates, and the evaluation of outcome not being blinded to which participants had been assigned to the active weight loss program or a control condition.

Nonetheless, the review suggested that at 12 months, Weight Watchers achieved 2.6% more weight loss then education/control comparison treatments. Jenny Craig had 4.9% greater weight loss. Nutrisystem did 3.4% better than education/control groups. These figures are long way from a difference of 24 pounds.

Harriet Brown on Obesity
Harriet Brown on Obesity

In an exceptionally evidence-based recent Slate article, Harriet Brown argued that it was time to stop telling fat people to become thin. Even when dieters lose weight in the short-term, 97% of them regain everything they lost in three years. The article criticizes studies evaluating weight loss programs because they typically have too short a follow up period.

I was also skeptical too about the disadvantages the author of the self-help book attached to the positive fantasies that dieters have. Most participants in weight loss programs  have unrealistic fantasies about how much weight they will lose. But the fantasies do not strongly predict the modest amounts of weight they actually lose. So, there is no argument for targeting unrealistic expectations and fantasies if the intent is only to improve weight loss.

I started my search for the evidence behind the claims in press releases that women with positive fantasies lost 24 pounds less than women with less positive fantasies. Using the author’s name and “weight loss” in Google Scholar, I immediately came to the article to which I could eventually tracked the claim.

Oettingen, G., & Wadden, T. A. (1991). Expectation, fantasy, and weight loss: Is the impact of positive thinking always positive?. Cognitive Therapy and Research, 15(2), 167-175.

But I couldn’t immediately see its relevance and so I kept looking. I stumbled upon a non-peer-reviewed chapter by the author made available on the Internet .

The chapter cited the same 1991 weight reduction study with Tom Wadden at Penn. But the chapter made a claim that was not obvious in the original paper:

After one year, patients with high expectations lost about 12 kg more than subjects with negative fantasies. After two years, the respective differences were 15 and 12 kg. These patterns of results stayed on change when subjects’ weight loss aspirations, as well as subjective incentives to reach their spy weight loss, were covariates. The findings that supported our assumption that optimistic expectations and positive fantasies a different types of optimistic thinking, and they have differential effects on motivation and action. Apparently, images of getting slim and resisting food temptations he did weight loss. Subjects seem to daydream that weight loss had occurred without their having to make any effort.

jesus saysAnd then I stumbled upon a later peer-reviewed overview article that also reviewed the 1991 Oettingen and Wadden study. It converted the kilograms to pounds and elaborated:

Participants with positive expectations about losing weight (i.e., ‘‘It is likely that I will lose the indicated amount of weight’’) lost on average 26 pounds more than those with negative expectations (i.e., ‘‘It is unlikely that I will lose the indicated amount of weight’’). However, participants with positive fantasies (e.g., those who imagined shining when going out with the friend and easily resisting the temptation of the leftover box of doughnuts in the lunch room) lost on average 24 pounds less than participants with negative fantasies (e.g., those who imagined having disappointed the friend and having a hard time resisting the leftover box of doughnuts in the lunch room). In short, while positive expectations predicted successful weight loss, positive fantasies predicted little success in reaching one’s desired weight.

So I gave the 1991 paper a closer look.

The abstract stated

We investigated the impact of expectation and fantasy on the weight losses of 25 obese women participating in a behavioral weight reduction program. Both expectations of reaching one’s goal weight and spontaneous weight-related fantasies were measured at pretreatment before subjects began 1 year of weekly group-treatment. Consistent with our hypothesis that expectation and fantasy are different in quality, these variables predicted weight change in opposite directions. Optimistic expectations but negative fantasies favored weight loss. Subjects who displayed pessimistic expectations combined with positive fantasies had the poorest treatment outcome. Finally, expectation but not fantasy predicted program attendance. The effects of fantasy are discussed with regard to their potential impact on weight reduction therapy and the need for further studies of dieters’ spontaneous thoughts and images.

From the method section I learned

  • Subjects weighted average of 106.4 kg with a BMI of 39.1. The recruited with advertisements seeking women at least 25 kg overweight.
  • 13 subjects were randomly assigned to a very low calorie diet and 12 were assigned to a balanced-deficit diet.

Such a small randomized trial can’t reliably give effect sizes for anything. At best it can only suggest the feasibility of doing such a trial of a larger scale. Weight related fantasies were not manipulated, but they were measured:

Weight-Related Fantasy. Each subject was asked to vividly imagine herself as the main character in for hypothetical weight-and food-related scenarios. Two stories were designed to elicit fantasies about the subject’s weight loss, worse to others describing cows were tempting foods. Each story led to an unspecified outcome with subjects were asked to complete (in writing) by describing the stream of thoughts and images that occurred to them. Care was taken to make the scenarios open ended in order to elicit a variety of responses. One of the scenarios is described below:

You’re just completed Penn’s weight loss program. Tonight you have made plans to go out with an old friend whom you haven’t seen in about a year. As you wait for your friend to arrive, you imagine

Subjects rated the positivity, negativity, and intensity of their responses to each scenario, as well as their imagined body shape (using seven-point scales; 1 = low, 7 = high). After completing one scenario, they proceeded to the next. Scores were averaged across all four studies to form positivity, negativity, intensity, and body shape scales.

The study also assessed participants’ expectations of reaching their goal weight with three related questions:

(1) “How likely do you think it is that during this weight reduction program you’ll lose the amount of weight (that you have specified)?”; (2) “you feel that you will be successful in the weight loss program?” and (3) “how confident are you that after this program is completed, you will watch the amount of weight you indicated in question 1?” Questions were answered using 7-point scales (1 = low, 7 = high).


The results suggested this exceptionally strict and long-term weight reduction program yielded some significant losses for both groups.

At weeks 17 and 52, weight losses for the very low calorie diet participants were 17.1 kg and 16.1 kg, respectively. Losses for the BDT balanced-deficit diet participants were 11.1 kg and 14.8 kg.

But where does the extraordinary claim about fantasies get support? That is really not clear from anything presented.

Weight-related fantasy predicted weight loss in week 17 (r = -.34, p = .05) but not in 52 weeks ( r = -.31, p = .09). But these numbers demonstrate the problem: with such a small number of participants, something can be significant at .34, but not at the trivially different .31. Beam me up, Scotty, nothing interesting happening here.

The authors then undertook multiple regression analyses that were inappropriate for a number of reasons. [Warning! Briefly getting technical ahead] First, with so few subjects, the equation was overfit with too many independent variables: initial weight, fantasy, and expectation were entered simultaneously in the first step; the interaction between fantasy and expectation in the second. Weight at weeks 17 and 52 were dependent variables of the two analyses, respectively. The second issue is that with expectations and fantasy correlated .45, entering both of these variables simultaneously would lead to misleading results, probably different than if they were entered alone.

In these dubious complex analyses, positive fantasies were not significant at 17 weeks, but were at 52 weeks. If anyone is still taking these analyses seriously, these are contradictory results. But who cares?

The authors then furthered their illusion by graphing the interaction effect, crossing fantasies with expectations. Think of it: they only had 25 patients and they nonetheless graphed participants after creating three groups (low, medium, high) based on fantasy scores and then 3 groups based on expectations(low, medium, high). We can’t take these results seriously.

So, I can find no basis in this study for the claim that women having positive fantasies lost 24 fewer pounds versus those having less positive fantasies. There was no randomization with respect to fantasies and no results justifying such an astonishing claim. We’ve got numbers, but not science here, and no basis for claiming that this self-help book is more sciencey than its competitors. But citing numbers is impressive, particularly when it’s so hard to find out from where they came.

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So we have the reality of most people who try to lose weight won’t succeed and certainly they won’t succeed in keeping it off. And probably at some point during that time, they fantasize about what would be like to be slimmer. We should give them a break. Instead, the author gives them reason to feel bad about themselves by suggesting that somehow WOOP could have saved them. Weight loss is that much under their control. And they can still save their dignity by buying this book. And if they don’t succeed in losing such weight, they just haven’t integrated the exercises of the book into the lives enough.

Okay, the author was capitalizing on a 1991 study that she’d probably completed long before she even thought about the book – Dare I say, before she fantasized about the book? – And the idea to try to turn the article into a promotion of the book was not a good one.

welcome to woop woopBut in a forthcoming blog, maybe not my next, I will critique another study that she published when she was working on the book. It serves as an experimercial in promoting the book. The study claims that a drop of only 1 mmHg in systolic blood pressure in women told to have positive fantasies about how they will look in high heels represents a serious sapping of energy that can be generalized to real world situations. Yep, experimercial . I’m going to introduce a new and very useful term to link the packaging together and publication of weak studies when they serve the promotion of commercial products. That’s a lot more of what positive psychology is about then we recognize.

Finally, why are supposedly scientific organizations like British Psychological Society Division of Health Psychology hawking a self-help book with a weak relationship to science that is likely to mislead consumers with its pitch?


(*) British Psychological Society President-elect, Peter Kinderman says he is frightened by his positive fantasies of “winning Nobel prizes, winning Pulitzer prizes, being elected to this and that, being awarded knighthoods,” but he’s an odd bird.


6 thoughts on “Do positive fantasies prevent dieters from losing weight?”

  1. “…why are supposedly scientific organizations like British Psychological Society Division of Health Psychology hawking a self-help book…”

    I don’t know why this particular book but perhaps they are attempting to show they are fair and balance. Except that saying negative thinking impacts outcomes is just like saying positive thinking does. It is all about someone’s thoughts not actions, circumstances or others actions.


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