What Drives People to Overeat

Dr. Zanni is a psychologist and healthsystems specialist based in Alexandria,Virginia.

Twenty years ago, few psychologistsstudied eating behaviors,but interest in food psychologyhas expanded with America's waistline.Some of the most interesting findingsare featured in Mindless Eating, a bookby Brian Wansink, PhD. Dr. Wansinkconducts research on eating behaviorsat his Cornell University laboratory,which resembles a restaurant, a cafeteria,and a television den, and simulatesenvironmental, social, and cognitivevariables.

Consider this environmental cue:serving bowl size. Participants servingthemselves from either gallon-sizebowls or half-gallon-size bowls ate 59%more snacks from the larger bowl.

And cognitive expectations? Whileeating identical meals, subjects receiveda complimentary bottle of wine fromeitherNoah's Winery, California, orNoah's Winery, North Dakota. The bottlescontained the identical inexpensivewine. Those with the California label ate11% more food, lingered an extra 11 minutes,and rated the food and wine higherin quality, compared with those receivingthe North Dakota label. The participants'belief that California wines arebetter affected their entire meal (knownas the halo effect). Similarly, peoplewill order Belgian Black Forest DoubleChocolate Cake with greater frequencyand rate it higher than the same menuitem simply called Chocolate Cake.

How strong are cognitive expectations?In one study, approximately 60%of participants in a darkened room whowere given chocolate yogurt, but toldit was strawberry, rated it as having agood strawberry taste.

Final Thought

Knowledge is not power in this area.Subjects who attended a 90-minute lectureon food psychology still fell victimto cues. Food psychology helps identifycues and thoughts fueling overeating—cues that clinicians might use to a dieter'sadvantage.

Did You Know?

• Individuals are aware of only 20 of theirdaily average of 200 food decisions.
• The more people like the food, the fasterthey eat.
• Individuals eat 28% more popcorn duringsad movies than happy movies.
• Females prefer ice cream, chocolate,cookies, and other snacks as comfortfood; males prefer ice cream, soup, pizza,or pasta.
• More comfort foods are consumedwhen happy than when bored, lonely, ordepressed.
• Individuals pour and drink 25% to 30%more when given a short, wide 22-ounceglass, compared with a tall, thin 22-ounceglass.
• The larger the package, the more peopleeat: 23% more spaghetti, 48% morecandy, 53% more popcorn. The sameoccurs with healthy foods.
• The longer people watch television, themore they eat.
• Less is eaten on hot days and more oncold and rainy days.
• Individuals eat 35% more food when eatingwith others, with one notable exception;overweight people eat less wheneating with thin diners.
• Inconvenience decreases consumption.Placing candy 6 feet away led participantsto eat approximately 50% less thanwhen the candy was on their desks. Incafeterias, people eat less if they have topurchase chips or candy at a separatecounter.
• Real or perceived variety increases consumption.Subjects who sampled 6 candiesmixed together consumed almost50% more than subjects who sampled 6single flavors separated into 6 bowls.
• People consume less when given consumptioncues. Participants ate 28%fewer chicken wings when the boneswere left on the table than those whoseserver periodically removed the evidence.