July 27, 2014 at 10:26 AM ET
Put down that large serving spoon. Step away from the all-you-can-eat buffet. A new study published in the International Journal of Obesity finds that most people eat 92 percent of what they put on their plates.
“If it is on your plate, it will be in your stomach,” says Brian Wansink, one of the authors of the study and also of the book, “Slim by Design: Mindless Eating Solutions to Everyday Life.” “A lot of people feel guilty by being part of the clean plate club; it is by far what most of America and the world [does]; clean their plates.”
That's right, it's not just Americans. Researchers from Cornell University's Food and Brand Lab observed the eating habits 1,179 people from eight different countries—the United States, Canada, France, Taiwan, Korea, Finland, and the Netherlands. They found average adults eat almost all of what they put on their plates.
Wansink, the John S. Dyson Professor of Marketing, said these findings can help people modify their behaviors in a positive way and reduce bad eating habits.
“Interestingly, what we found was there was no difference between men and women,” he says. Only children left food behind, with most only eating 59 percent of what’s on their plates (no surprise to most parents).
“If your kid doesn’t clean a plate, it doesn’t mean [she has] eating problems, it means [she’s] normal,” he says. “They don’t know what they like or don’t like and they don’t really know how big their stomachs are.”
Most people do not know how hungry they are and over-serve themselves. And, adults don’t want to feel like they made a mistake by over-serving themselves, he says, so they try to finish what’s on the plate.
“Subconsciously, we don’t like to think we have bad judgment and we made a mistake … [this is] part of what motivates people to eat that last little bite,” says Wansink.
Since the 1970s, portion sizes have increased dramatically and experts believe this is one reason that obesity rates have skyrocketed. A 2003 study found that a serving of orange juice was 40 percent bigger than it was 20 years earlier; simply drinking a larger glass of juice daily could mean an extra five pounds on the waistline.
The USDA recommends that Americans eat smaller portions and suggests that people manage their food intake by measuring the food and using smaller plates. When eating out, the USDA says people should consider ordering smaller sizes or sharing larger portions. People also need to listen to their bodies and stop eating when they feel full.