In the market for new dinnerware? Shopping around for new table linens? You might want to take a moment and consider what two professors have to say. Neither are interior designers – Brian Wansink is a specialist in consumer behavior and Koert van Ittersum, is a marketing expert, nor do they even have an amateur’s affinity for home decorating, probably.
What they do have, however, is something much more valuable, the key to how you and your whole family can shed weight without even thinking about it. Enough about mindless eating, this is mindless weight loss – genius. All this, as you continue feeding the fold the same meals, at the same time, at the same table. No catch? No catch. According to a paper to be published in the August 2012 issue of the Journal of Consumer Research by Wansink and Van Itterum, you simply have to be discerning in how you select the dinnerware you use - paying attention to both size and color, and the hue of your tablecloths.
The paper reaps its findings from five studies which involved nearly 200 participants. Among their tasks, the subject were asked to serve themselves Campbell’s tomato soup in different-sized bowls, serve themselves cereal in different-sized white bowls over white or black tablecloths, and serve themselves a cream-based white Alfredo sauced-pasta in either red or white plates at a buffet.
It’s been known for some years that the size of your dinnerware impacts on how much you serve yourself (or others if you’re playing host/hostess, or mom/dad). You pile less fodder into smaller plates or bowls, and vice versa. Makes sense, right? After all, your gluttony is curtailed by spatial limitations. But, it’s not just a physical lack of space, or an abundance, that determines the disparity in how food is portioned out. In 2005, Wansink, of Cornell University, and van Ittersum, of the Georgia Institute of Technology, showed that when consumers were asked to spoon a target amount of soup into bowls of various sizes they were just as apt to overfill large bowls as they were to underfill small bowls even when they were focused on pouring exactly the same amount into all the containers. The researchers knew then that there was something going on in the human brain that makes us unconsciously misjudge serving amounts depending on the size of dinnerware. But at the time, they couldn’t explain the phenomenon.
Lucky for us, they can now. In their paper, the researchers show that an optical illusion of relative size perception proposed by the 19th Century Belgian philosopher, Franz Delboeuf, is responsible. The theory describes how a circle that is surrounded by a slightly larger circle is perceived to be larger than it actually is, whereas a circle that is surrounded by a much larger circle is perceived to be smaller than it actually is. “ It’s basically a question of how our brain processes information and to simplify things to make sense of them,”explains Van Ittersum in a phone interview. Translate this to food on a plate. “It’s easy to think of soup in a bowl as comprising of two circles,” says Van Ittersum. “If you consider say a 10cm diameter of soup as reflecting your target serving size, you’ll project that onto whatever dinnerware you are using. If it’s a really big bowl, the Delboeuf illusion kicks in, and that 10cm circle looks smaller than it is, so you say to yourself, no, no that’s not it yet. So what do you do? You serve yourself a lot more than 10cm!”
How much more, is much more, then. If you’re a proponent of sprawling plates and steep, wide-rimmed bowls, you could end up serving 9% to 31% more than you typically would. The impact on your waistline is deleterious – eating only 50 calories more a day (the equivalent of 2 Hershey kisses) because of too-big plates could result in a five- pound weight gain each year. So the diktat is clear: buy “smaller” dinnerware. But it’s not that easy. Wansink and Van Ittersum found that the average size of the American-manufactured dinner plate has increased by almost 23% from 1900. Having procured a variety of plates produced over the last century on eBay.com, they noted that plates were just over 9 inches in 1900, around 10 inches in 1950 and creeping towards 12 inches in 2010. “The more people want, the more manufacturers give and everyone wins – the consumers are happy, the manufacturers can charge higher prices and their profit margins go up,” theorizes Van Ittersum, “Even I love big plates, when you set the table they look great, everyone wins in the process, but the ultimate outcome isn’t necessarily favorable.”
Van Ittersum suggests that the plate-size of the 50s – an era where only 9.7% of Americans were clinically obese compared to 34% today, would be a good model to go by when kitting out your kitchen. Judging by what’s available in today’s stores, you might have to circumvent dinner plates altogether in favor of more diminutive salad plates. Problem solved….or not. “The problem is having just one plate that works for a range of foods, since serving sizes vary, say Van Ittersum. “Beyond that serving sizes are different for different people.” Whether you want it or not, you can get much more steamed broccoli out of your daily calorie allowance than baked ziti with extra cheese, so there’s no optimum plate size to compensate for the effect of the Delboeuf illusion. “My main recommendation is to have two sizes of plates. If you’re eating very healthy food opt for the bigger plate, if it’s a less healthy meal, use the smaller plate. Still I don’t suggest you eat your dinner from a coffee cup saucer.”
If relinquishing your fashion-forward penchant for large dinnerware seems too sizeable a sacrifice to bear, don’t worry – you can still keep the threat of obesity at bay. The authors of the study found two significant means of minimizing the effects of the Delboeuf illusion – or rather, what they call plate or bowl-bias. Size here, isn’t the only thing that matters. It turns out color is important too. The more significant the contrast between the color of the food on the plate and the color of the plate itself, the less impactful the illusion is, and vice versa. “If you present red sauce and pasta on a red plate or pasta with white Alfredo sauce on a cream-colored plate, you’ll over serve,” explains Van Ittersum. “Because your brain has to work harder to distinguish the food from the plate, the effect of the illusion amplifies, and the inverse is true. To take advantage of this, white plates which provide a strong contrast to most foods, are probably your best bet.”
For the pragmatists among you scoffing at the notion of throwing out your too-big china, and then shelling out for various-sized plates in various colors, scoff no more. There’s a more cost-effective way out of impending weight-gain. The color of your tablecloth is also crucial in determining whether you overeat or undereat. This time though, you want the least amount of contrast as possible between the plate and the tablecloth. “The idea here is that you more or less eliminate the effect of the second circle and thus the Delboeuf illusion. Consumers are no longer distracted by the outer circle, or the size of the plate.”
The sum significance of Wansink and Van Ittersum’s findings in this paper is considerable. Nutritionists and public health experts will be able to usefully harness the information to help patients and consumers achieve a healthy weight by making environmental changes rather than “mental changes” that are much more difficult to implement. “Having to pay attention to what and how much you are eating all the time is unfeasible and that’s why most people who lose weight tend to put it on again,” says Dr. Melina Jampolis, a leading physician nutrition specialist, and the author of "The Busy Person's Guide To Permanent Weight Loss". “The research is clear, from the age of about four, we eat with our eyes, not our stomachs. With these kind of visual, environmental cues that can be easily integrated in a lifestyle, people can mindlessy lose weight in a way that leads to permanent change.”
Change isn’t limited to the domestic domain though. Chefs, restaurateurs, national fast food and quick service chains can incorporate Wansink and Van Ittersum’s findings without compromising neither the taste and recipes of their offerings, nor their bottom line. “People are so distracted by talking, eating, and the noise and movement around them in restaurants that they are not going to notice a change in their plate size. They’re certainly not going to measure the china,” says Karen Ansel, a spokesperson for the Academy of Nutrition and Dietetics. Because of the effect of the Delboeuf illusion, the change in portion sizes would be barely perceptible to diners. Indeed, the restaurant industry could follow the example set by food manufacturers who are reducing the sodium content of their products. “Chefs can take the lead. They don’t need t0 announce it, they can just quietly reduce the size of their dinnerware, or change the tablecloths in the same way that food companies are reducing salt without alerting consumers. Sure there’s a cost involved in procuring new china or linens, but there’s an even bigger cost involved with obesity”
Since the Delboeuf illusion influences people at such a profound, unconscious level, even when consumers are educated to its effects, and serve themselves with careful attention and awareness, plate or bowl-bias, though lessened, is almost impossible to eradicate. “Anyway, who can serve without distraction at the breakfast or dinner table with the whole family around? What are you going to say: be quiet, I’m serving? That’s just not going to happen!” offers Van Ittersum.
What's the answer, then? Go shopping.