May 23, 2012— -- Once you pop open a stack of potato chips, it can sometimes be hard to stop until you suddenly realize you are scraping the bottom of the can. Now, new research suggests that inserting colored potato chips might actually help curb your appetite -- and the findings could have implications for other snacks, too.
Researchers at the University of Pennsylvania and Cornell University gave students one of two types of Lays' Stackable potato chips. The first group was given a stack of chips with red dyed, edible potato chips dividers that were interspersed at several different intervals, suggesting serving sizes anywhere from 5 to 14 chips. The other group was given the traditional stack of potato chips with no edible dividers.
What the researchers found was that inserting colored potato chips at regular intervals in the stacks caused people to eat fewer chips overall. In fact, the group with the edible serving size dividers reduced their potato chip consumption by 50 percent. The results appear in the May issue of the Journal of Health Psychology.
"The colored chip did all the work," says Paul Rozin, a professor of psychology at the University of Pennsylvania and one of the authors of the study. "This study showed that segmenting foods gets people to eat less.
"People tend to eat what you put in front of them. If you put less in front of them and give them a signal, they will take it."
Barbara Rolls, professor of nutritional sciences at Penn State and author of the Ultimate Volumetrics Diet, had similar observations. In a separate study, she and her colleagues found that giving men and women bigger bags of potato chips caused them to eat more. This increase in snack consumption, interestingly, did not translate into the participants eating less at dinner time.
So, is portion control the answer to why over one-third of Americans are obese today?
The answer may just be that simple. Rozin compared the American and French diet with some interesting findings. The French, he found, tend to eat smaller portions.
"Even the portions at McDonald's and the pizza parlors are smaller in France compared to America," Rozin says. "The idea in France is not eating as much as you can but eating as much good food as you can."
Rozin and his colleagues also found that the French tend to eat more slowly than Americans and savor each bite. In the United States, food is more on the run, and people do not realize how much they are actually consuming.
Interestingly, the French eat higher fat diets than Americans but they have lower rates of cardiovascular disease and higher life expectancy. Rozin explains that this is called the "French paradox." The French do not go to the gym as much as Americans but they are overall more active and control their portion sizes.
So what can we learn from the new study out this month and our French counterparts? Rozin and Rolls have several creative tips:
"You have to change your intake -- that's the point, "emphasizes Rozin. "Small changes make big differences."