Wednesday, July 26, 2006

Cornell Study On Portions Missing Key Element

Wansink says you can lose weight by using smaller bowls--HA!

This Forbes Magazine article shares about a new research study from a food marketing professor who found people actually eat more calories when they are given larger dishes. However, there are a lot of assumptions made about what this means for people desiring weight loss because it is missing a key element that exists in people who struggle with being overweight or obese.

Lead researcher Brian Wansink, director of the Ithaca, NY-based Cornell University Food and Brand Lab with expertise in Food Marketing, Consumer Behavior, and Food Psychology, conducted an experiment with 85 food and nutrition experts by inviting them to an ice cream social. The study involved randomly distributing one of two sizes of bowls (17-ounce or 34-ounce) and one of two sizes of serving scoops (2-ounce or 3-ounce). Everyone at the ice cream party was responsible for dipping their own ice cream.

Wansink noted that those study participants who were given the 34-ounce bowls, or double the size of the smaller bowls that were distributed, actually served themselves 31 percent MORE ice cream than those with the 17-ounce bowls. At the same time, the larger 3-ounce scoop resulted in a 14.5 percent INCREASE in ice cream serving size than the smaller 2-ounce scoop.

What was most amazing to Wansink, whose teaching and research interests look at how packaging and human behavior can impact how often and how much consumers use food products, was the fact that his unbeknownst to them study pool included so-called nutrition and food "experts" who would know how many calories are in a certain portion size. Nevertheless, they STILL ate more with the larger bowls and scoops.

"The fact that even they end up being tripped up by these cues just helps to show how ubiquitous and how subversive these illusions can be," Wansink exclaimed.

This is why restaurants keep serving larger and larger portions so they can charge you more money. And yet we still are encouraged as a society to clean our plates because we were taught to do that growing up (because God forbid that kid in Africa who is starving will be even hungrier if I don't finish every last morsel on my plate!). Is there any wonder how America got to be so fat?!

But I must take Wansink to task about one assumption he is making regarding his study and it is not directly addressed in the story. For those study participants who ate out of the 17-ounce bowls, how many of them went back for SECONDS (or THIRDS!) with the noticably smaller bowls? Hmmm?

While the 34-ounce bowls may have included about one-third more ice cream than the 17-ounce ones intially, you can't help but wonder if the bigger-bowl group skipped the second go round while the smaller-bowl group felt jipped and double-dipped! I sure would have back in the day when I weighed 410 pounds with a bottomless pit for an appetite!

You know, I bet they were cruel for this study and removed the ice cream before anyone could ask for seconds. Eeek! Tsk tsk to them if they did this because it totally ruined what would likely have happened had they continued to make the ice cream available. Lines would have started to develop with all the 17-ounce bowls getting filled up yet again. There's no doubt in my mind that this would have happened. We'll never know for sure with this study.

However, if you want to see some REAL human behavior concerning food, Mr. Wansink, then why don't you conduct THAT experiment again and watch what happens to your theory about smaller bowls when you let people eat all they want of the ice cream uninhibited by the self-imposed limitations of your study? That's precisely why I oppose the move to make restaurants cut portions and calories because people will simply order more food to satisfy their appetites. Plus, people now EXPECT to get large portions when they go out to eat and are disappointed when the portion sizes are TOO SMALL!

Since I started livin' la vida low-carb in 2004 and lost 180 pounds on this amazing lifestyle change, I have never once watched my portions and have simply let my body tell me when I have had enough food to eat. Some low-carbers have told me that they HAVE to watch calories and control their portion sizes, but I haven't run into this yet. While I certainly agree people should be eating less food and calories than they are right now, I don't think artificially trying to fool people into eating smaller portions by giving them smaller tableware is necessarily going to help people lose weight because they'll just go back and fill those smaller plates up again and again until they have eaten the amount they really want.

What people need to do is make BETTER food choices and stop worrying about calories and portions to help lower their weight and get healthy. That's why the 100-calorie foods are the biggest diet gimmick out there on grocery store shelves today. The formula I have used during my success is STILL working well for me in maintenance mode, too. Why should I change my strategy now?

Wansink said previous research has shown that many other factors influence how much food is eaten by people, including the different kinds of foods available, background music, how hot or cold the eating environment is, and the speed of the eating patterns of your dining partner. He said we can add to that list the size of the plates, bowls and other dishes now.

"Four ounces of ice cream in a small bowl may appear an appropriate amount for a mid-afternoon snack, but the same in a larger bowl may appear too small, leading one to over-serve," he concluded.

The results of this study appear in the September 2006 issue of the American Journal of Preventive Medicine.

You can e-mail Brian Wansink about his study at

8-7-06 UPDATE: Brian Wansink was on vacation when I wrote this blog post, but he was kind enough to reply to it upon his return.

Hi Jimmy,

Thanks again for sending me your link and for the thoughtful column on the "Ice Cream Illusions" article. You make excellent points in the article. I very much agree with your big point that if a person wants to lose a lot of weight a serious diet a low carb approach like the one you recommend can be very useful for a disciplined person (By the way, I LOVE the name of the book, Livinlavidalowcarb, very cool).

The main point of the ice cream illusions study (the bowls and spoons study) was to show how the environment can trick even experts. The people in the study were nutritional science profs and should have known better. I would have been just as guilty.

It was also a good point you made about people overcompensating by eating seconds. This can be a real problem in some studies and I've seen a number of studies in which it can really hurt the conclusions. To get around this problem we always try to use bowls that far exceed the size a person would fill.

For instance, in this study we gave people either 17 oz or 34 oz bowls. Even with the smaller 17 oz bowls, the average person fills it less than 1/3 full. The size of the bowl is no real constraint in how much a person eats. It can however be a perceptual constraint.

These ideas are a couple of the chapters in a forthcoming book (Oct 17 from Bantam Dell) called "Mindless Eating: Why We Eat More Than We Think." Let me know if I can be of help to you in the future, and best of luck to you and your readers.

All my best,


EXCELLENT! Brian said he would be sending me a copy of his book to review when it is available. Stay tuned...


Blogger LCforevah said...


I'm still reading Colpo's book, and one of the frightening things that keeps coming up is the amount of wishful thinking coming from the researchers themselves.

It's incredible wishful thinking to believe that an adult or even a child wouldn't know enough to serve themselves seconds if the bowl they're using is too small.

Heck, that was my trick as a child, using a small bowl for a snack, and then surreptitiously refilling it so I wouldn't get comment from my parents !

7/27/2006 4:39 PM  
Blogger helen said...

mmmmmmm, eat everything in moderation. But who's moderation are we talking about???

7/27/2006 9:44 PM  
Blogger The Happy Low Carb Taco said...

The bowl thing kinda works for me. *shrugs*. Oh well. But the moderation thing always struck me as stupid. There are some things you should NEVER EVER eat.

For me, ice cream is that thing.

Now I am sad. :(

7/27/2006 10:17 PM  

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