I’ve just read Dr. Traci Mann’s popular book, Secrets from the Eating Lab, which came out in April (and is hence a “new book” at my library at the moment…). I had some real hopes for this book on dieting, obesity, and the psychology of eating. Mann has some fame in behavioral psychology, and her lab at the University of Minnesota is influential. Plus she just wrote an op-ed that Oprah Winfrey’s investment in WeightWatchers is a smart business move because diet failure, which leads to repeat customers, is a built-in and stated profit strategy for the company. Mann points out it’s the same logic that runs casinos. Big revelation? probably not, but still a good point and illustrative of the circular logic in popular American diet culture.
So about Secrets from the Eating Lab. The tone of the book is personable and it’s a quick read–a couple of hours will cover it. But…it’s not really a very good book and it makes Mann look a little like the huge parade of airheaded “pundits” who show up on Fox News and Good Morning America and Dr. Oz to talk about emotional eating right before presenting a plate of “healthy treats” that turn out to be brownies.
OK, it wasn’t quite that brainless. I even liked a lot of what Mann had to say about how to live an integrated life and not obsess over weight. But the book is a very good example of why someone who’s reasonably expert in one facet of diet research may not be the right person to interpret other areas for the public.
The behavioral studies are interesting and entertaining. Although the findings are not altogether news anymore, the lab setups she and her team used to demonstrate them are fun to read about. A sample of the psych experiment findings, which are the strongest part of Mann’s book:
- The eating style of your companions is likely to influence you pretty strongly when you eat as a group. Her lab tested this in an entertaining series of experiments.
- “Determination and willpower” is more wishful thinking than a successful diet strategy for a lot of people, and structuring your environment is more effective.
- Keeping a bowl of treats even more than arm’s length away from you reduces your likelihood of grazing, and if you actually have to get up and walk to get more, you probably won’t.
- People eat more when distracted with screentime or eating while driving or whatever than when focusing on their food.
- Smaller plates lead to greater satisfaction with less food.
- Offering vegetables at the school cafeteria before serving the rest of lunch, and without competition from french fries, gains a much higher rate of takers than when there are other foods available.
- Announcing foods as “healthy” is a turn-off.
- Most intriguingly, “comfort food” is no more effective than any other food, or even no food, for recovery after an emotional shock.
All of these findings mesh with common sense, and few of her recommendations are implemented as regularly as one would like in daily life at school or work. But the behavioral studies from her lab are only a small part of the book, one or two chapters in the middle. Where Mann runs into trouble is nearly everywhere else. Put bluntly, she’s way out of her depth in the larger world of academic obesity research, and neither she nor most of her readers or even, crucially, her book editor seem to know it.
The main themes of Secrets from the Eating Lab are 1. that diets don’t work, 2. obesity is not the deadly killer everyone assumes it is, and 3. therefore you should stop obsessing and be healthy in other ways, for example by exercising to relieve stress.
These claims are stated as blanket facts rather than opinions she wants to explore, even when she bolsters them with studies. Outside of her own lab’s experimental framework she makes fundamental and glaring misstatements and assumptions of fact that can easily be disproven. The result is not markedly better than what you might expect from a high school debate team’s background prep for the season topics, “Do Diets Work?” and “Does Obesity Kill?”
In the “diets don’t work” chapter, Mann scours the literature for a largeish number of diet studies in which subjects attempted to lose weight, then winnows the 300 or so studies down to about 26 that meet her criteria of a randomized controlled study with reasonable participant recruitment and retention. Although some studies demonstrated short-term weight loss or differential success between two test diets over the course of weeks, months or a year, longer followup revealed no net loss and a large degree of regained weight among participants, and most of the studies had a lot of dropouts before completion. Moreover, most were less than carefully conducted and relied on self-reported weight and diet recall from the subjects rather than weigh-ins and so on.
Well, fair enough. But she doesn’t look at more recent and stringent work, as a nutrition researcher would be expected to. And she doesn’t really explore what the behavioral environments of the experiments might have contributed–something she might have been able to lend better insight into. Continue reading
Filed under: books, DASH Diet, Diabetes, Food Politics, nutrition, unappetizing | Tagged: diet research, Eating Lab, obesity research, Traci Mann | Comments Off on Lackluster “Secrets” from the Eating Lab
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