Food illusions: why we eat more than we think - Cover Story

We're very suggestible to numbers, just like we're suggestible to labels. If the store says, "Limit 12 per person," people say, "I don't need 12." But on average, they buy seven, compared to when there's no limit, they buy three.

Taste

Q: How do restaurants influence what we eat?

A: We did a couple of studies in restaurants where we described 12 menu items that had either a normal name like Chicken Breast or a name like Tuscan Sun-Kissed Breast of Chicken. Or, we'd say either Chocolate Cake or Belgian Black Forest Double Chocolate Cake. But the foods were exactly the same.

After people finished their meal, we'd ask them about the taste or texture. People who ate the generically named items would say, "The taste was OK." And they said "not very likely" when we asked if they'd order it again.

But if they ate the exact same foods that were descriptively named, they'd say, "Gee, that was pretty good. I like the taste." And they said they'd be more likely to order it again.

Q: So our expectations influence our taste buds?

A: Yes. Researchers in the sensory sciences believe that the senses don't lie. They say that if your tongue tastes vanilla, there's vanilla in there.

I believe our senses are more suggestible, particularly within a reasonable range. If you say, "Would you like some filet mignon?" and it's actually cat food, people would figure it out. But I think there's a loose relationship between reality and perception, while there's a strong relationship between perception and your behavior--whether you eat a food or buy it again or tell somebody else to eat it.

Q: So if people expect food to taste good, it will?

A: Yes. One reason we did studies on names on menus is that the person in charge of nutrition at the University of Illinois cafeteria, my colleague and coauthor James Painter, was trying to get people to eat better. He wanted to see if changing a food's name from "Skanky Squash" to "Illinois Prairie Squash" would get people to think it was better.

And it worked really well, particularly for vegetables and the main dishes. For the desserts, it wasn't quite so good, I think because desserts taste so good anyway, there's a ceiling effect.

Q: And if people expect a bad taste, that's what registers?

A: Yes. We gave people energy bars with absolutely no soy in them. We asked them what they thought of the taste when the wrapper said "contains 10 grams of protein." And they'd say, "Not bad ... kind of chocolatey ... good texture."

But when the label on the exact same bar said "contains 10 grams of soy protein," they'd say, "Oh geez, I can't get the taste out of my mouth ... this is terrible ... doesn't even taste like chocolate." If people imagine they're going to taste something, they're going to look for it.

Q: How can we help people eat healthier foods?

A: You can't just tell them that they shouldn't eat chips or candy or meat. You have to convince them that there's an alternative.

If you're trying to convince somebody to eat, say, an apple instead of candy for a snack, you can either emphasize that the apple is similar to candy, that it's sweet, it tastes good, or you can emphasize the differences--it's healthy, it's got fiber, etc.