Mindless Eating by Brian Wansink, PhD (2006, Bantam)
My review (out of 5 stars):
I don’t own too many books whose cover features a rave review from O: The Oprah Magazine. I also don’t own any other book that might remotely fit in the category of “diet advice books”. Most of that genre, in my opinion, ranges from despicable to utterly useless. But this book is different.
It is also a book I know well. The occasion of my writing this review is having completed reading the book cover to cover for the fourth time. Three of these read-throughs have been in conjunction with a class of senior psychology students as part of a course called The Psychology of Eating and Drinking Behavior.
Mindless Eating was written by Brian Wansink, a decorated scientist who holds an Endowed Chair at Cornell University. While Wansink’s book is full of practical advice for people trying to control their weight, his suggestions are evidence-based. He is a research scientist with a gift for designing revealing experiments of impressive creativity. While one could probably lose weight by applying Wansink’s many suggestions, for me the joy of the book is as a fellow research scientist appreciating the cleverness of the studies he has designed and carried out.
But even as a practical book on dieting, this one is different. Many popular diets are focused on physiology – and often on unproven physiological theories, or theories generalized far behind evidentiary support. Thus we get low fat diets, or low carb diets, or protein diets, or restriction diets, or avoid processed foods, or eat what our caveman ancestors ate – any number of theories borne out of the belief that what we eat is crucial, and that what we have been eating isn’t good for us.
Wansink makes no such suggestions about what we should or shouldn’t eat. Wansink is a “calories in – calories out” theoretician – he believes that what we eat is not nearly so important as how much we eat. This shifts the attention away from understanding physiology and toward understanding behavior. The issue for him isn’t what happens to the food as it goes from our intestines into our bodies, but rather as it goes from the package or the plate or the buffet line into our mouths.
Another refreshing perspective in Wansink’s book is that he doesn’t really have any villains, other than that old classic – human nature. He doesn’t blame fast food companies, or modern farming practices, or marketers, or any of the other favored targets of our modern ills. To be sure, all of these are important aspects of our food environment which collectively make gaining weight easy, but the solution to gaining weight isn’t to battle these behemoths – it is to control our own local environments.
Enter the clever experiments. A movie popcorn bag adorns the cover of my paperback version of the book, alluding to an experiment in which he gave free popcorn to movie-goers in exchange for patrons filling out a short survey at the end of the movie. The popcorn was purposefully made stale (popped several days in advance), and patrons were either given a large container or a medium container (the medium still so large that no one could eat all of it). The result? Patrons given the large container ate considerably more than patrons given the medium container. Again, since no one even came close to finishing the medium container, the implication is that the size of the package – more than the taste of the food or the filling of our stomachs – suggests how much we should eat at a sitting. Consider this the next time you open a huge bag of potato chips that’s mostly air – the bigness of the container may cause you to overeat.
His book covers many replications and extensions of this package size effect. In one case, invitees to an ice cream social put away more ice cream when given a larger bowl and/or a larger scoop to serve themselves with. In another, Wansink invented a bottomless soup bowl, in which research subjects ate tomato soup out of a bowl that was unnoticeably being refilled from below. Again, while even the control group (eating from normal bowls) didn’t finish all of their soup, the bottomless group at almost twice as much – favoring the opinion of their eyes over the opinion of their stomachs.
Wansink and others have also studied whether this prejudice of the eyes can be used to someone’s advantage. He mentions the work of Barbara Rolls, who made smoothies for two groups of subjects. In one group, she whipped the smoothies longer, which adds more air to the mixture, fluffing up the smoothie. Thus one group was eating a smoothie with half as many calories as the other, but in both cases the smoothie was one full glass. Each group was equally satisfied, and the amount they ate at a later meal depended not on how many calories were in the previous smoothie, but rather how filling the previous smoothie looked to the eye.
In Wansink’s version, he had students attending a Super Bowl watch party with an all-you-can-eat chicken wing buffet. For half the tables, servers removed the bones as the chicken wings were consumed, and for the other half of the tables, the wing bones were allowed to pile up. The students who could see the evidence of their consumption – the bones piling up – ate less than those whose tables were frequently bussed. Both groups could rely on their stomachs, but didn’t. Informally, Wansink says he leaves empty wine and beer bottles out at parties he throws, to reduce the alcohol consumption of his guests.
Besides visibility, relatively minor increases in the amount of effort required to get access to food can have surprisingly large effects. Moving a candy dish across the room – still visible, but now requiring an office worker to get up and take a few steps to obtain it – decreased eating behavior substantially. Wansink suggests making food just slightly more difficult to obtain as a general strategy. Plate your food in the kitchen rather than at the table, so getting a second helping requires returning to the kitchen. Pour potato chips into a bowl, so getting more requires getting the bag out of the pantry again. Move fruit and vegetables out of the crisper drawer and onto the middle shelf of the refrigerator to increase the probability of selecting a healthier snack. In school lunch rooms, he suggests moving healthy snacks next to the register into “impulse buy” position.
Another set of studies examined the effect our expectations have on our appreciation of food. Subjects given strawberry yogurt to eat in the dark believed in was chocolate yogurt simply because they were told so. Subjects given brownies on a paper napkin rated it less tasty and were less likely to buy more than subjects given the same brownie on fancy china. Patrons in a test restaurant presented with a free bottle of North Dakota wine spent less time eating their food and rated their meal as less appealing than patrons eating the same meal given a free bottle of California wine. In reality, the wines were identical with only labels changed.
Similar effects were seen in a Hardees restaurant in which one room was temporarily given a make over to play calming music, table cloths, and table service. The same fast food was rated as tasting better and patrons spent an extra 10 minutes enjoying their meal during a busy lunch hour. Back in the test restaurant, half of the diners ordered from menus with plain food descriptions, and the other half ordered the same food from menus loaded with adjectives. The adjective menu diners ate more, rated the experience more highly, and hung around longer. Think about that the next time you’re deciding between the “value-menu hamburger” and the “Chiabatta bacon cheeseburger” at Wendy’s.
Expectations can also create what Wansink calls health halos, which can actually be quite dangerous to someone watching their weight. For example, most people consider Subway to be one of the healthier fast food restaurants, but Wansink’s research shows that this knowledge can lead people to presume that everything at Subway is healthy and also that this gives them permission to overindulge there. Subway’s sandwiches may in fact be a healthier option than, say, a Big Mac, but if one then orders double meat, mayonnaise, a large soda, and a cookie, the advantage may be gone. Similarly, Wansink found that if people were given a bag full of granola that was (misleadingly) labeled low-fat or low-calorie, people would eat far more from that bag than other people given an unlabeled bag. Low calorie doesn’t mean no calorie – if you eat more of a low-calorie food because it’s “healthy”, then at some point you’ll eat more total calories than if you just stuck with the regular version. Even products labeled “heart-healthy” or “full of vitamins and minerals” – products making no overt claims about their calorie content – will be overconsumed on the mindless assumption that healthy in one respect means healthy in all respects.
The implications of Wansink’s work are simultaneously depressing and inspiring. It is depressing to realize that so much of our food behavior is mindless and cognitively impenetrable – that is, no matter how much education we have on these topics, we will still succumb to these environmental cues. (In one study Wansink trained students on the effect of package size on intake and even his educated students failed to moderate their selection of foods from larger bowls when put to the test.) But on the other hand, these cues can be tremendously effective at reducing intake when arranged to our advantage. Buying smaller plates, buying tall-and-thin glasses instead of short-and-fat glasses, plating food in the kitchen, increasing the apparent size of food by spreading it out or fluffing it up with air or low-calorie ingredients like lettuce on a burger, placing healthy items on the most visible shelves, placing candy dishes across the room (and in opaque containers) – simple environmental engineering can have a large impact over time. Wansink points out that all many of us have to do is eat 100 calories too little rather than 100 calories too much and, over time, we manage our weight.
This concept of environmental engineering needs to become better known among our nutritional gatekeepers – the ones who buy and prepare our food. Often this is mom or dad, but it also includes our politicians now that obesity has become a cause celebre and given that public school children get a large portion of their weekly calories in our schools. So much effort is now being wasted worrying about what we feed our kids at lunch, and too little attention has been given to the environments in which we feed kids lunch. Too much effort is spent on educating people about their food choices, and not enough effort on creating an environment in which people make the right choices whether educated or not.
Wansink’s book is about food, true, but it’s more about human behavior and decision making. I therefore recommend the book to anyone who is a human who eats food.