ITHACA, New York (CNN) -- We are powerless to ignore the clarion call of the candy jar, the beckoning of the buffet, the summons of the snack cupboard.
At the Cornell Food and Brand Lab, Professor Brian Wansink studies how people behave around food.
That's the conclusion of Brian Wansink, author of "Mindless Eating" and head of Cornell University's Food and Brand Lab.
Wansink has spent a career watching how people behave around food -- at home and work, in sit-down restaurants and buffets, and in the many other places where Americans routinely chow down.
"We believe we have all the free will in the world. We believe we overeat if the food is good or if we're really hungry. In reality, those are two of the last things that determine how much we eat," Wansink says. What really influences our eating, he says, are visibility and convenience.
In one experiment, Wansink placed candy jars of chocolate in office workers' cubicles for a month. Then, he moved the candy six feet away. Simply having the candy closer meant the office workers ate five more candies a day. That adds up to 125 calories a day, or 12 pounds a year. Take an interactive quiz on eating and your environment »
"Something that's very visible, every time we see it we have to make a decision. Do I want to eat that? Do I not want to eat that? Do I want that candy on my desk, or do I not want it? We can say no 27 times, but if it's visible, the 28th or 29th time, we start saying, 'Maybe.' By time 30, 31, we start saying, 'What the heck? I'm hungry,' " Wansink says.
"In a similar way, convenience also tends to do the same thing. If it's really convenient and there's nothing to stop us from reaching out and grabbing something, we'll continue to do something until something tells us to stop."
In one telling experiment, Wansink divided a group of 150 test subjects into three, giving a third canisters of potato chips with every seventh chip dyed red. Another third received canisters with every 14th chip dyed. Other ate from canisters with no dyed chips.
Test subjects with no dyed chips ate an average of 23 chips; those with every 14th chip dyed red ate an average of 15; those with every seventh chip dyed red ate an average of 10. Watch examples of food marketing in TV ads »
The red chips provided what Wansink calls a "pause point," an interruption that forces the eater to ask whether he or she wants to eat more. For this reason, Wansink says the 100-calorie containers of chips or cookies work to help 70 percent of people eat less. When they finish the container, they pause and ask themselves whether they want more.
Wansink has found you'll eat more if you're eating:
• "family style" with the serving bowls on the table.
• directly from the bag or carton.
• on a bigger plate or from a bigger container.
• in front of the television, in the car, with friends.
Even if we know all about mindless eating, Wansink says we can't help ourselves. He's proven this point by giving a 90-minute class to graduate students about eating more from larger containers and then secretly observing them at a Super Bowl party six weeks later.
Wansink's solution: Surrender. Accept that you will give in to temptation and eat mindlessly.
What really influences our eating, he says, are visibility and convenience. Keep healthy snacks close at hand.
"When it comes down to it, we're efficient people," Wansink says. "We want something that's convenient. And if it's fruit or vegetables that's a whole lot more convenient than that cake that's wrapped up in the freezer, guess what's for snack today? Fruits and vegetables." E-mail to a friend
David S. Martin is a senior producer with CNN Medical News.
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