You've heard a thousand versions of diet and weight-loss advice, but now there's some advice that finally makes sense: use small plates.
The information comes out of the Food and Brand Lab at Cornell University, where food is served to students in a place that looks like a restaurant. The diners become guinea pigs to uncover the secrets of our eating habits.
Servers tell diners to take as much as they want, and the test subjects are given a free meal if they simply rate the food. A man, acting as a waiter, tells a diner to go get some water. That's an excuse for him to take the plate and secretly weigh it before bringing it to the diner and then doing something quite unappetizing.
Each person gets their food coughed on because that gets them to take a second plate and serve themselves again. But the trick is that the second plate is a different size, either bigger or smaller than the first one. This test is not really about rating the food, it's about whether people take less food when they have small plates. And almost everyone put 25 percent more food on a bigger plate.
Why? "We eat with our eyes, not with our stomach," said Brian Wansink, a food psychology professor at Cornell University, who conducted this research and wrote the results in a book aptly called "Mindless Eating." "We really don't pay much attention to what we eat, or how much we eat," Wansink added.
According to Wansink, most people think they know when they're full, but in reality, people don't really know when they're full.
So should we all use small plates? Is that the answer?
"Absolutely," Wansink said. "Even tall, skinny glasses, because these are mindless ways to actually control how much we eat."
The glass reference comes from his tests that found even professionals, like bartenders, pour less into tall skinny glasses than short wide ones.
When Wansink asked 45 bartenders to pour drinks, they averaged 30 percent more liquor into the short, fat glasses.
Another experiment Wansink ran analyzed people's eating behaviors when it comes to leftovers. In one of his marketing classes, Wansink passed out bags of Wheat Thins and told the students they were leftovers.
His researchers had carefully created different kinds of bags, weighed them and put 44 Wheat Thins in some bags and only 11 in others. Half the class members got one of the big bags containing 44 crackers, while the other half got four separate bags containing 11 crackers in each bag.
At the end of the class, the bags were examined to see how many crackers were eaten during class. Findings revealed that students with the one big bag downed 50 percent more crackers than the students given the four smaller bags.
"There's a real tendency to kind of continue to mindlessly eat, because there's no place to tell you it's time to stop until you hit the bottom of that bag," Wansink said. "Our nature is to eat as much as we can as fast as we can.
It's something to think about when you're watching television, said Wansink. Don't bring in the full bag of junk food, just put some in a bowl, then you have a stopping point. You'll have to get up if you want more.
"Most people believe they overeat because they are really, really, really hungry, or because the food is really, really, really good," Wansink said. "What we find is that these two things are probably the last things that influence how much a person usually eats."
Wansink found in a candy test the key to unlocking what really influences our eating. He offered people jellybeans and M&M's. After offering both candies to many subjects, he found that when he altered the snacks so there is less variety, people eat much less. So, in one area of the room, the jelly beans and M&M's are separated by color. So instead of that appealing variety, you get just blue M&M's.
"Just changing the colors of M&M's ends up increasing how much people take by about 50 to 70 percent," Wansink said.
And, Wansink said, this is exactly why people eat more at buffets. He suggests you can lose weight at a buffet by telling yourself to start with just two items.
None of us want to believe that we are really duped or fooled by something as simple as the itty-bitty cues around us in the environment. According to Wansink, we are; but there are small things we can do to take back control and eat less mindlessly.
Wansink suggests doing a few things. First, slow down the pace at the dinner table by using chopsticks with Chinese food, for example. Second, create a stopping point by putting snacks into smaller bags and by using smaller plates, smaller spoons for that ice cream and taller, skinnier glasses for drinks. Last, recognize that variety, the kind you get at a buffet, leads to overeating.
By just making those little changes, he said, in a year, people lose weight and feel better.
This report originally aired on October 20th, 2006.