BACKGROUND: Brian Wansink is a food psychologist at Cornell University who focuses on the how and why people eat. For instance, he can tell you if you get more beer from a tall skinny glass or a short fat glass. His Food and Brand Lab tries to help people eat more nutritiously and to help control how much they eat. An additional focus is on increasing the acceptance of soy foods and the consumption of fruits and vegetables. He oversees a series of test kitchens, restaurants and cooperating grocery stores to understand how consumers “choose and use” foods.
SIZE (AND SHAPE) MATTERS: Wansink and his colleagues conducted two studies of 167 people demonstrating that both children and adults pour and consume more juice when given a short, wide glass compared to those given a tall, narrow glass – although they believed the opposite to be true. Those with the short wide glasses poured 76% more juice than those with the tall slender glasses. The bias is caused by a visual illusion known as the vertical-horizontal illusion: we tend to focus on heights instead of widths, so we are more likely to over-pour into wide glasses while thinking we poured very little because of the shorter height.
FAT-FREE ISN’T CALORIE-FREE: Wansink has also found that people will eat more of a snack – even one they don’t like very much – if it is labeled “low fat.” IN fact, low-fat cookies, for example, only have about 30% fewer calories than regular cookies, while low-fat granola only has 12% fewer calories. In one study, people given low-fat granola ate 35% more – 192 extra calories – than those who thought they were eating regular granola. The low-fat label leads people to mindlessly overeat a product, while believing they are being “health-conscious.” Wansink’s advice: if you’re going to indulge, eat something you truly enjoy – just eat half as much of it.
SEE WHAT YOU EAT: The human stomach isn’t designed to keep accurate track of how much we have eaten. In fact, it takes about 20 minutes after we eat before our stomachs register that we are “full.” Visual cues are critical to controlling our much we eat, according to Wansink. Students participating in an all-you-can-eat chicken wing buffet ate continually if their tables were continually cleared, because they couldn’t see how many they’d already consumed. Here’s a handy tip for your next buffet: people who put everything on their plate before they sit down to eat – including dessert – eat about 14% less than people who take smaller amounts and go back for seconds or thirds. He also advises people not to eat snacks out of the box; put it into a separate dish and leave the box in the kitchen. You will eat less if you can see how much you’ve already eaten.