Sheila's Nutrition Digest Vol. 9 - Food Psychology: What is controlling your eating?
By: Sheila Kealey (2005/09/29)
Have you finished a bag of chips when you only wanted a few? Do you eat only when you are hungry? If physiological cues were the sole determinants of our eating habits, the nation's obesity and health statistics would look quite different! Ubiquitous food marketing and advertising make it obvious that many other factors have a huge impact on what we eat and how much we eat.
Brian Wansink, PhD, is a researcher who is passionate about figuring out how cues that aren't related to hunger influence our eating habits. Dr. Wansink wants to use this information to help us control how much we eat and choose nutritious foods, which contrasts the food industry's single minded goal of encouraging us to eat more of their product. As professor of Marketing and Nutritional Science, and the director of the University of Illinois' Food and Brand Lab, he has conducted over 100 studies looking at eating behavior.
Through lab experiments, hidden cameras, in-depth interviews, and consumer panels, his work has revealed some fascinating information about how environmental cues influence what we eat. Here's what we can learn from some of his findings:
1. Beware of Package Size
BIG packages encourage us to eat more, even when the food isn't great.
When Wansink gave moviegoers popcorn in large-sized buckets, they ate almost 50% more than those served popcorn in smaller buckets. Both groups estimated that they'd eaten the same amount of popcorn. Were they overeating because the popcorn tasted so good? Not likely – the test subjects were munching on stale, 14-day-old popcorn, showing how automatic some behaviors become, and how package size has a powerful influence over the amount we eat.
In another series of studies, Wansink looked at consumption of 47 different grocery store products and found that people generally poured more out of larger packages than smaller ones.
Make it work for you:
If you're concerned about reducing your caloric intake, opt for small plates and bowls at home, and be aware of the sizes of containers and plates when eating out. Select large packages of foods you want to eat more of (e.g., those big bags of salad greens), and small packages of foods that you are trying to limit.
2. Out of Sight, Out of Mind
We're likely to eat more candies if the candy bowl is on our desk rather than just 6 feet away. Wansink studied the behavior of secretaries, and found that they consumed 50% more Hershey's kisses when they were within arm's reach as opposed to a few steps away. The type of bowl influenced consumption too: people ate more candy if the bowl was clear and they could see the candy, than when an opaque bowl stored the candy. They found that the same applied to healthy foods – for example, people ate more carrots when they were directly in front of them than when they had to get up to eat them.
Make it work for you:
Surround yourself with healthful foods. At parties, you're better off within arm's reach of the vegetable platter than the chip bowl. Keep unhealthy foods out of sight, or don't bring them home from the supermarket in the first place. As nutrition expert Dr. Marion Nestle has said: “If you resist it at the grocery store, you only have to resist it once. If you take it home, you have to resist it every hour of every day.”
3. We Eat with Our Eyes
The more we see, the more we eat.
Wansink's group designed a clever experiment to show the powerful influence visual clues exert on how much food we eat. They rigged up a self-refilling soup bowl (a “bottomless” bowl where soup refilled from a hidden hose at the bottom of the bowl connected to a pot of soup). Unsuspecting college students who ate their soup from the self-refilling bowls ate 73% more soup than those eating from normal bowls, but both groups reported the same degree of “fullness.” This study shows we often use visual cues, like the amount of food left in a bowl or on a plate, to figure out when to stop eating, rather than relying on feelings of fullness.
Make it work for you:
Don't feel you have to “clean your plate,” but try to become more aware of adequate portion sizes and feelings of fullness to figure out when to stop eating.
4. Optical Illusions
We perceive that tall, slender glasses hold more liquid than short, wide glasses.
Wansink conducted studies showing that visual illusions cause us to pour more and consequently drink more when we use short, fat glasses. Researchers gave people either tall, slender 22 oz. glasses or short, wide 22 oz. glasses. People poured about one third more liquid into the short, wide glasses than the tall, slender glasses, although they thought they poured less into the short glass. In another study, Wansink showed that even bartenders were susceptible to this vertical-horizontal illusion, pouring about 28% more alcohol into tumblers than highball glasses.
Make it work for you: Pay attention to the glass shape: since short, wide glasses encourage us to drink more, use these for beverages that you want to consume more of, and save tall, slender glasses for beverages that you want to limit.
5. Variety Makes Us Eat More
Many studies suggest that being presented with a variety of foods makes us eat more.
Wansink examined this phenomenon with M&M's. He compared eating patterns of bowls containing ten M&M colours vs. bowls containing seven M&M colours. People ate 25-30 percent more M&M's out of the bowl with ten colours compared to the bowl with seven colours, even though all M&M's taste the same.
Make it work for you. Look for variety in healthful foods, since a variety of nutrients is the foundation of a healthful diet. For example, you will likely eat more vegetables if you are presented with a combination of colourful options rather than one type of vegetable. Eating this variety ensures that you'll benefit from more protective nutrients that are important for good health. Also, recent research has demonstrated that nutrients from different foods may interact to provide extra health benefits, suggesting that that your diet is more than the sum of its parts.
6. Our Expectations Influence Our Taste Buds
People eat more when a food has an enticing, creative description rather than a plain name.
Even when two foods are identical, people rate the food with the most descriptive name as tasting better. Descriptive menu-item labels can increase food sales and improve attitudes customers have towards the food and the restaurant, according to Wansink's research. For example, “New York Style Cheesecake with Godiva Sauce” got better ratings than a simple “Cheesecake,” though both were identical. People even indicated they'd be willing to pay almost 10% more for a descriptive menu item. Wansink believes that associations that evoke positive memories or emotions like nostalgia, locations, or sensory descriptions will influence our perception. What would you choose: Grandma's Famous Sugar Cookies or Sugar Cookies? Tuscan Sun-Kissed Breast of Chicken or Chicken Breast?
Make it Work For You: Don't be fooled by descriptive labels at the supermarket – and you won't have to look far to find many good examples creative and enticing names! At home, present your healthful dishes with great names, and your guests may find them more satisfying!
Since most of us can feel hunger and already have a general idea of nutritious foods to eat, being more aware of other powerful influences on our food choices can go a long way to help us adopt a nutritious diet.