Trying to diet and eating too much…
Can it be that adding food makes people believe they are eating less?
A recent study by Brian Wansink and Pierre Chandon report that this can indeed be the case (this version of the study was done with John Tierney of the NYT)
Half of the people were shown pictures of a meal consisting of an Applebee’s Oriental Chicken Salad and a 20-ounce cup of regular Pepsi and they were asked to estimate the amount of calories in the entire meal. The other participants were shown the same salad and drink plus two Fortt’s crackers prominently labeled “Trans Fat Free.” The crackers added 100 calories to the meal, but given that they were “diet” how will their presence influence the estimated amount of calories in the entire meal?
The first group estimated that the meal contained 1,011 calories, which was a little high. The meal actually contained 934 calories — 714 from the salad and 220 from the drink. But, the second group estimated the total amount of calories to go down. Now the average estimate for the whole meal was only 835 calories — 199 calories less than the actual calorie count, and 176 calories less than the average estimate by the other group for the same meal without crackers.
The original study was interpreted as a halo effect of items labeled as diet. I suspect that this is correct, but I think that it is also possible that people have a hard time computing totals and that instead they compute averages – which makes the estimation when the crackers are present to be lower.
My latest book, The Upside of Irrationality, explores some positive and some negative ways that irrationality plays out in our lives.
Interesting. I wonder if they had another condition where there were the same salad, drink, and crackers but without “Trans Fat Free” label.
Dear Irrational,
In graduate school and an analyst position 2 years ago, I specifically studied the behavior of consumers with regard to healthier food choices.
Perhaps you’ve heard of UFood Grill? Landmark Center is the closest location for you in Cambridge, I wonder what sort of halo effect may in play there.
I digress. My feeling is that yes, the halo effect exists, but that studying it at the cracker-level may miss the halo effec that John Tierney discusses Subway enjoying.
Studying calorie estimations is fascinating, in that it forces the consumer to numerically value each meal. But I think this methodology may fail to encompass all of those beautfil irrationalities that govern the improper human decision to eat the cracker-laden salad.
I don’t think that consumers reevaluate each meal – perhaps the decision to eat healthier often begins at which restaurant to enter. If the entire restaurant of Subway enjoys the halo effect, they only need to convince a McDonald’s customer that Subway has a few menu items of superior nutritional compositoin – or less calories.
I am doubtful that customer’s pursuant visits to Subway, and pursuant sandwich choices inside of the restaurant rely on any sort of prosaic analysis of caloric content. Instead, the consumer, flooded with conflicting information and tortured by conflicting emotions of responsibility and the desire for satiety, chooses based on a larger brand association (Subway / McDonald’s) and then allows the ‘halo’ to close the cognitive dissonance that results from ordering the 12 inch Italian sub with extra oil and prosciutto.
I suppose that I completely agree with the conclusion – but might suggest that a probing of consumers’ emotions about eating and emotions about the brands associated with eating may reveal additional insight about the emotional / irrational tendencies that also govern general misperceptions about what is and is not good for us.
Thanks for you work in this field! I am an avid fan of your work, and eager reader of this blog.
I think there may be a mix of the halo/averaging effect. Consumers more items decrease the “effort per item” so they are suceptable to assumption and rounding. This leads the assumption that if the crackers are healty the salad will not be loaded with junk either… the halo affect.
db
Love the work and your take on life.
I agree about the Halo effect but let’s treat the cause not the symptom. Sleep on a set schedule for at least 6.5 hrs per day, exercise moderately, and eat moderately. Do not touch that pepsi. The deleterious effects of the corn syrup used in many of our products contribute to this nations issue with Fat. Fast foods in general also contribute to the issue. Our lazy choices and lack of discipline regarding sleep, exercise and diet are the Cause.
It seems to me that the above is irrelevant. If you eat till you feel stuffed you will gain weight, and if you stop before you are full, you won’t. That’s the way it always worked for me.
This makes sense in context with the nutritionism theory that Michale Pollan exposes in “In defense of food”.
This example reminds me of base rate neglect. In the classic experiment, subjects are provided with a short description of a woman with details that suggest she may have feminist leanings. Subjects then assign probability estimates to various possible facts about the woman. Base rates are neglected by subjects as they often rate the probability that the woman is a feminist bank teller as higher than the probability that she is merely a bank teller. Has anyone previously drawn a connection between halo effects and base rate neglect?
Браво, какие нужные слова…, отличная мысль
My opinion is a bit another how it is possible to talk to the author, for example on an e-mail?
hm. hope to see same more info
Excuse for that I interfere … here recently. But this theme is very close to me. Write in PM.
Possibly the most important aspect of dieting is the lifestyle changes which ought to accompany the start of the diet program.