According to author Brian Wansink, we make more than 200 food-related decisions every day — most without really thinking about them. Slim by Design takes Wansink’s surprising research on how we make those decisions and turns it into actionable tips.
This is part of Lifehacker’s book review series. Not every life hack can be summed up in a blog post, so we’ve decided to review some of our favourite life-changing books for deeper dives into life’s most important topics.
The tips are all based on food psychology research, most of it from Wansink’s own lab at Cornell. You know Wansink’s research even if you don’t recognise his name. We’ve covered his stuff dozens of times here at Lifehacker, like when we told you to use tall, skinny wine glasses to avoid overpouring, or to eat an apple on your way to the supermarket, or when we let you in on the restaurant menu tricks you’re probably falling for. He wrote an earlier book about this research, Mindless Eating.
Wansink’s career started with degrees in business, journalism and marketing — so he’s not a dietician or doctor, but instead comes from the angle of studying consumer behaviour. Today he’s the director of the Cornell University Food and Brand Lab, where his team studies how factors like lighting, plate size and your dinner companions affect what and how much you eat.
His line of work is the same as that of the researchers at food companies that try to come up with ways of getting us to buy more. He argues that this isn’t a conflict of interest, that companies love when we eat less, because then their costs are less. He presents 100-calorie packs (his invention, he claims) as an example of this. Wansink gleefully told food company execs that people will pay more to eat less, and he turned out to be right. On the other hand, 100-calorie packs are kind of irritating and I’d rather not overpay for my food. (Wansink suggests a solution, of course: buy the big bag and repackage it yourself.)
The book is written as a guide to taking advantage of food psychology research. Rather than paying more attention to your food choices, Wansink wants you to continue eating mindlessly, but structure your environment so that the easy choices are the better ones. In other words, you’re designing your environment to make (or keep) you slim. He sums up the philosophy like this:
For 90 per cent of us, the solution to mindless eating is not mindful eating — our lives are just too crazy and our willpower’s too wimpy. Instead, the solution is to tweak small things in our homes, favourite restaurants, supermarkets, workplaces, and schools so we mindlessly eat less and better instead of more. It’s easier to use a small plate, face away from the buffet, and Frisbee-spin the bread basket across the table than to be a martyr on a hunger strike. Willpower is hard and has to last a lifetime. Rearranging your life to be slim by design is easy.
The changes he suggests range from really easy things, like facing away from the buffet when you choose your seat at a restaurant, to bigger jobs like reorganising or even relocating your pantry.
Who This Book Is For
This book is for people who want to geek out on the bizarre ways our minds work, while learning tips to make healthy eating easier.
Far from a dry list of tips, this book is packed with sidebars, anecdotes, illustrations, fun facts and best of all stories about how food research is done. He talks about fitting old-school cameras into tissue boxes to snoop on shoppers in supermarket aisles, and later moving to an even cleverer water-bottle-based disguise.
Wansink is, after all, the guy who rigged up a literally bottomless soup bowl to show how we rely on serving sizes to regulate how much we eat. That story, and a lot more insider information on how food psychology research is done, are covered in Mindless Eating, Wansink’s earlier book. Slim by Design grew out of that one, when people started asking him how to put the research into action in everyday life.
The book doesn’t stop at fixing your kitchen and office, though. More than half of it is dedicated to things restaurants, employers, supermarkets and school lunchrooms can do to promote healthy choices (and get people to pay more for less food.) He suggests that if you’re serious about this, you can volunteer to help your school’s food director revamp the canteen — sample letters and talking points are provided. Or you can pester chain restaurants and friends on social media; he provides a handy list of social media accounts and suggested hashtags.
What You’ll Get
First, you should know that you’ll be reading a lot of corny jokes and hey-look-how-cool-I-am pop culture references. Some people will find his style irritating, so consider yourself warned. I read it more as awkward dad humour, and find it whimsically dorky. (He lists “semi-terrible stand-up comedy” as one of his hobbies, so if you like his style, who knows, maybe you can catch him live sometime.)
Wansink is the kind of guy who not only explains his jokes, but does so in footnotes.
The book is broken into five sections on the different domains where you can take action: home, restaurants, supermarkets, workplaces and school cafeterias.
Each has a 100-point scorecard to help you rate whether the environment — say, your house — is promoting healthy choices or not. You get points for having a TV-free kitchen, for example, and for keeping your breakfast cereal out of sight. The scorecards also act as handy cheat sheets, since now you know that you should put the cereal in a cabinet. For restaurants, if you’re not a restaurant owner, Wansink encourages you to use the scorecard as a tool for comparing your favourite restaurants to each other. If a place scores low, maybe you shouldn’t visit there as often.
The last chapter is packed full of tips for using the other chapters’ tips. (Yo dawg, we heard you like tips.) There is, of course, a four step plan:
- Identify the places where you eat most often: your home, two favourite restaurants, one supermarket, plus your workplace and your kids’ (if any) school.
- Pick one thing to change in each place. Wansink stresses that trying to change everything at once is pretty much guaranteed to backfire.
- Ask your favourite food places to help, through social media and snail-mail letters (examples provided).
- Share your success. Tweet the heck out of it, basically.
This section is surprisingly thoughtful, and suggests plans of action for people who like to talk to restaurant managers as well as people who would prefer to passive-aggressively leave copies of workplace wellness articles on their boss’s desk. The school-focused action plans all start with the overlookable but critical step of thanking the lunchroom manager for all they do and offering help before criticism.
One Trick You’ll Take Away
Probably the handiest tip is the idea that we eat better when healthy foods are convenient and attractive, and when unhealthy foods are out of sight. This isn’t just one tip, but really a constellation of them. To paraphrase just a few, from the chapter on homes and kitchens:
- Pre-cut fruit and vegetables, and put them in see-through containers or baggies.
- Cover all your healthy leftovers in plastic and the unhealthy ones in foil.
- Put those baggies on the most visible shelf in the fridge.
- Put the less healthy food in the sides and back of the fridge.
- Also position healthy food front and centre in your freezer, cabinets and pantry.
Even though this is pretty obvious once you think of it, you probably haven’t implemented it in every area of your kitchen. For example, did you think of wrapping aluminium foil around the ice cream container in your freezer so you don’t have to look at the label every time you open the door? I didn’t think so.
While this book is fascinating and I plan to implement some of the tips, there’s a tiny problem: The title. Is it really fair to say that these design changes will make us slim? While I trust Wansink’s single meal experiments (like the one where people piled more red-sauce pasta onto red plates than onto white plates, and vice versa), he oversteps when he presents these little hacks as solutions to changing your health or body weight over the long term.
Wansink takes for granted that eating less (or healthier) at a given meal will make us lose weight, but shaving off a kilojoule here and a kilojoule there doesn’t make the kilograms drop off. Little to none of his research extends beyond what happens at a single meal or shopping trip. If fruit sales doubled in a school lunchroom that followed his advice, does that really imply that the kids ended up healthier because of it? Wansink relies on his imagination (and ours) to fill in the gaps, but just because a technique should make us slim doesn’t mean it actually accomplishes that as a long-term goal.
Some of his studies attempt to address the long-term issue by looking at the habits of slim and overweight people, and how they differ. Slim people are more likely to make a lap around the buffet table before serving themselves, for instance, and are more likely to use chopsticks instead of forks. He does make sure to say that these are observational studies, and that we don’t know for sure that using chopsticks makes people lose weight (for example, it’s correlation, not causation). But that distinction gets lost when Wansink proudly announces that a chain of Chinese buffets, after consulting with him, now provides chopsticks by default.
This study, and others like it, tickled my bullshit detector. When Wansink and his team snooped on people in buffets, they recorded 103 variables, from whether they put a napkin in their lap to how many times they chewed their food. And they reported on whatever things the skinny people did more. But some of the results are probably flukes. I spoke with Rebecca Goldin, a statistician from George Mason University and director of STATS.org. She shared my concern. The findings aren’t automatically wrong, she said, but Wansink’s team analysed them in a way that could easily let bogus results creep in.
So take the tips with a grain of salt. I’m not convinced that keeping a blender on my kitchen counter will make me healthier (a tip from a study comparing skinny and overweight people’s kitchens), but I will gladly check out the whole buffet before choosing my food. Even if it wasn’t what made those thin diners thin, it’s still good advice. With that caveat, I still think this is a good book. Wansink’s approach of making healthy choices easy is far more realistic than expecting people to calculate kilojoules every time they reach for a snack.
It also makes for a handy template to improve public places without causing controversy, like when he was called in to help a school food director who had banned chocolate milk and was catching hell for it. Within weeks, students were boycotting the lunch lines and the town paper had blasted her in a front-page article. Wansink had her bring back the chocolate milk, but put it in an inconvenient spot so kids had to make a twenty-second detour to get it. Most didn’t bother. This pragmatic approach is what makes Slim by Design so valuable: it takes human nature into account. That’s a better plan than trying to put up with rules we’d rather not follow, or summon willpower we don’t have.