food psychology and overeating professor brian wansink food & brand lab -- director

Food Psychology and Overeating Food Psychology and Overeating

Professor Brian WansinkProfessor Brian Wansink

Food & Brand Lab -- DirectorFood & Brand Lab -- DirectorCornell UniversityCornell University

We Examine the“Whys” Behind What Consumers Eat

Who?Who? 6 Profs from 5 depts6 Profs from 5 depts 7 graduate students7 graduate students Hidden camera observation Hidden camera observation

lablab 2 restaurants; 1 snack room2 restaurants; 1 snack room A 3400 person national A 3400 person national

consumer mail panelconsumer mail panel 5 cooperating stores5 cooperating stores

How?How? Lab experiments Lab experiments Field studiesField studies Consumer panelsConsumer panels Data-base miningData-base mining In-depth interviewsIn-depth interviews ““Hidden” In-kitchen camerasHidden” In-kitchen cameras

Since 1990 . . .Since 1990 . . .• 115 studies115 studies• 43 referred journal articles43 referred journal articles• 1 book (& 1 forthcoming)1 book (& 1 forthcoming)• 70% focuses on consumption70% focuses on consumption volume & frequencyvolume & frequency Marketing

Nutrition

2004-Brian WansinkU of Illinois Press

New

What Unknowingly Influences What Unknowingly Influences Consumption?Consumption?

There Might be Systematic ExplanationsThere Might be Systematic Explanations• Step 1. Uncovering the Systematic BiasesStep 1. Uncovering the Systematic Biases• Step 2. Explaining these BiasesStep 2. Explaining these Biases

Consider a Shopping Related Warm-up Consider a Shopping Related Warm-up ExampleExample

Warm-up Shopping Example:Warm-up Shopping Example:Why Do We Buy Too Many?Why Do We Buy Too Many?

Which Sign Sells More . . .Which Sign Sells More . . .

• Limit 12/personLimit 12/person vs. vs. No Limit/personNo Limit/person

• 3 for $3.003 for $3.00 vs.vs. 1 for $1.001 for $1.00

• Buy 18 for the weekendBuy 18 for the weekendvs.vs. Buy some for Buy some for the the

weekendweekend

Wansink, Brian, Robert J. Kent, and Stephen J. Hoch (1998), “An Anchoring andAdjustment Model of Purchase Quantity Decisions,” Journal of Marketing Research, 35:1(February), 71-81.

Why Do We Buy Too Many?Why Do We Buy Too Many?

We focus on We focus on whatwhat to buy to buy . . . not . . . not how manyhow many

We are highly suggestible to numerical signsWe are highly suggestible to numerical signs• We anchor on their numbers and adjust our purchase from thereWe anchor on their numbers and adjust our purchase from there• Examples: Examples: 1212 per person per person 33 for 99¢ for 99¢ Buy Buy 66 for snacks for snacks• We say, “I usually buy 1 or 2, but . . .”We say, “I usually buy 1 or 2, but . . .”• Numerical signs can end up doubling how much we buyNumerical signs can end up doubling how much we buy

““Oh, but that never happens to me . . .”Oh, but that never happens to me . . .”

Wansink, Brian, Robert J. Kent, and Stephen J. Hoch (1998), “An Anchoring andAdjustment Model of Purchase Quantity Decisions,” Journal of Marketing Research, 35:1(February), 71-81.

Two Topics for Today . . .Two Topics for Today . . .

1. How the Size and Shape of Containers 1. How the Size and Shape of Containers Influence ConsumptionInfluence Consumption

2. Taste Suggestibility2. Taste Suggestibility

Beware of the Size and Shape of Beware of the Size and Shape of ContainersContainers

General Finding About Package Size . . .General Finding About Package Size . . .

Study 1. Hungry for Stale Movie Popcorn?Study 1. Hungry for Stale Movie Popcorn? Study 2. Do Shapes Bias Consumption?Study 2. Do Shapes Bias Consumption? Study 3. The Philadelphia Bartender StudyStudy 3. The Philadelphia Bartender Study Study 4. How about a Different Form of Fat?Study 4. How about a Different Form of Fat?

Package Size Increases Package Size Increases ConsumptionConsumption

People who pour from larger containers People who pour from larger containers eat more than those pouring from smalleat more than those pouring from small• Consistent across 47 of 48 categories Consistent across 47 of 48 categories • Obviously, up to a pointObviously, up to a point• Mediated by price per unit (RMediated by price per unit (R22= only 23%)= only 23%)

Additional rationale . . .Additional rationale . . .• There are no concerns of “running out”There are no concerns of “running out”• More difficult to monitorMore difficult to monitor

Criticism -->This only applies to hedonic Criticism -->This only applies to hedonic or tasty foods. For instance, the effects or tasty foods. For instance, the effects would be less for unliked foods.would be less for unliked foods. 0

100

200

300

400

500

600

700

"Small-x" "Medium-2x" "Large 3x"

SpagettiCrisco OilM&Ms

General Finding:Package Size Can

Double Consumption

Wansink, Brian (1996), “Can Package Size Accelerate Usage Vo lume?”Journal of Marketing, Vo l. 60:3 (July), 1-14.

1. Hungry for Some Stale Movie 1. Hungry for Some Stale Movie Popcorn?Popcorn?

General QuestionGeneral Question• Does food quality moderate?Does food quality moderate?• Any interesting gender effects?Any interesting gender effects?

The Field Study The Field Study (Chicago, IL)(Chicago, IL) • Movie was Mel Gibson in “Payback”Movie was Mel Gibson in “Payback”• Free popcorn (“Illinois History Week”)Free popcorn (“Illinois History Week”)• 2x2 Design2x2 Design

Large vs. X-Large Popcorn (pre-weighed)Large vs. X-Large Popcorn (pre-weighed) Fresh vs. 10-day-old PopcornFresh vs. 10-day-old Popcorn

• After the movie, ask questions & weighed popcornAfter the movie, ask questions & weighed popcorn

Wansink, Brian and SeaBum Park (2001), “At the Movies: How External Cues andPerceived Taste Impact Consumption Vo lume,” Food Quality and Preference, 12:1(January), 69-74.

We Eat Much More from Big We Eat Much More from Big ContainersContainers

People eat 45-50% more People eat 45-50% more from extra-large popcorn from extra-large popcorn containers than large containers than large onesones

They still eat 40-45% They still eat 40-45% more with stale popcornmore with stale popcorn

0102030405060708090

100

LargeBucket

Extra-Large

Bucket

Fresh

10 DaysOld

Grams Eaten

Wansink, Brian and SeaBum Park (2001), “At the Movies: How External Cues andPerceived Taste Impact Consumption Vo lume,” Food Quality and Preference, 12:1(January), 69-74.

2. Do Serving Container 2. Do Serving Container Shapes Bias Consumption?Shapes Bias Consumption?

Piaget’s Conservation of VolumePiaget’s Conservation of Volume• Kids think tall vessels hold more than wide Kids think tall vessels hold more than wide

vessels vessels • They fixate on 1 dominate dimension (height)They fixate on 1 dominate dimension (height)

This should influence the consumptionThis should influence the consumption• If tall glasses are thought to hold more . . .If tall glasses are thought to hold more . . .

They should over-pour in to short wide glassesThey should over-pour in to short wide glasses But they should believe they under-pouredBut they should believe they under-poured

Wansink, Brian and Koert van Ittersum (2003), “Bottoms Up! Peripheral Cues andConsumption Vo lume,” Journal of Consumer Research. December, forthcoming.

2. Do Serving Container 2. Do Serving Container Shapes Bias Consumption?Shapes Bias Consumption?

133 adolescents133 adolescents at a “Nutrition & Fitness Camp” in NHat a “Nutrition & Fitness Camp” in NH

Cafeteria at breakfast timeCafeteria at breakfast time• Each was randomly given one glass when arrivingEach was randomly given one glass when arriving• Tall narrowTall narrow juice glass juice glass or a or a Short wideShort wide juice glass juice glass

After exiting the line . . .After exiting the line . . .• Asked some usage & perception questionsAsked some usage & perception questions• Usage volume was weighedUsage volume was weighed


Yes . . . Container Sizes and Yes . . . Container Sizes and Shapes Bias Usage VolumeShapes Bias Usage Volume

These vigilant “weight watchers” These vigilant “weight watchers” poured 88% more into short wide poured 88% more into short wide glasses, but glasses, but believedbelieved they poured they poured lessless

Also true with adults Also true with adults (Jazz camp musicians in Westfield, MA)(Jazz camp musicians in Westfield, MA)

Hmmm . . . does this still happen Hmmm . . . does this still happen with experts and a specific target with experts and a specific target volume (say 1.5 oz)?volume (say 1.5 oz)?

0123456789

10

TallSlenderGlass

ShortWideGlass

AmountPouredEstimate

Ounces of Juice


3. Do Peripheral Cues Influence 3. Do Peripheral Cues Influence Experts with Precise Target Experts with Precise Target Volumes?Volumes?

48 Philadelphia bartenders48 Philadelphia bartenders• Paid $4 to be involved in a study Paid $4 to be involved in a study

on “consumers”on “consumers”

• Given 4 tall, slender (highball) Given 4 tall, slender (highball) glasses or 4 short, wide (tumbler) glasses or 4 short, wide (tumbler) glassesglasses

• Given 4 full 1500 ml bottles and Given 4 full 1500 ml bottles and asked to pour … asked to pour …

• Split in to . . . Split in to . . . Less than 5 years experienceLess than 5 years experience More than 5 years experienceMore than 5 years experience

Pour gin for gin & tonicPour gin for gin & tonicPour rum for rum & CokePour rum for rum & CokePour vodka for vodka tonicPour vodka for vodka tonicPour whiskey for Pour whiskey for

whiskey/rockswhiskey/rocks

HighballGlass

Tumbler


““When in Philadelphia, Should I Ask for a When in Philadelphia, Should I Ask for a Tumbler or a Highball Glass?”Tumbler or a Highball Glass?”

Bartenders poured 28% more Bartenders poured 28% more alcohol into tumblers than highball alcohol into tumblers than highball glassesglasses

Experience doesn’t eliminate biasExperience doesn’t eliminate bias

So, as a responsible bartender . . .So, as a responsible bartender . . .• Etch pouring marks on glasses Etch pouring marks on glasses • Use highball glassesUse highball glasses

0

0.5

1

1.5

2

2.5

TallHighball

Glass

ShortTumbler

Glass

< 5 years

5+ years


4. Does the Form (or type) of Fat 4. Does the Form (or type) of Fat Influence its Consumption Influence its Consumption Volume?Volume?

Is Olive Oil Healthier than Butter?Is Olive Oil Healthier than Butter?• Not if people over-pour.. . Not if people over-pour.. . • But do they?But do they?

• Two Italian restaurants: Champaign, ILTwo Italian restaurants: Champaign, IL

• People randomly given butter or olive People randomly given butter or olive oiloil

Secretly video-taped Secretly video-taped Coded by mystery dinersCoded by mystery diners

• Two measures . . .Two measures . . . How much fat was eaten (oil or butter)How much fat was eaten (oil or butter) How much bread was eatenHow much bread was eaten

Wansink, Brian (2003), “Interactions Between Forms of Fat Consumption and RestaurantBread Consumption,” International Journal of Obesity, forthcoming.

People Ate More Olive Oil per Slice, People Ate More Olive Oil per Slice, But They Ate Fewer Slices of BreadBut They Ate Fewer Slices of Bread

They ate 16% more fat/sliceThey ate 16% more fat/slice They ate 19% less breadThey ate 19% less bread A total calorie punch-lineA total calorie punch-line

• Don’t focus only on target foodsDon’t focus only on target foods• Focus also on companion foods Focus also on companion foods

00.5

11.5

22.5

33.5

44.5

OliveOil

Butter

Grams of Fat/SliceSlices of Bread

I knew that

Wansink, Brian (2003), “Interactions Between Forms of Fat Consumption and RestaurantBread Consumption,” International Journal of Obesity, forthcoming.

II. Can Labels Change the Taste of II. Can Labels Change the Taste of Foods? Foods?

Study 1. The Curse of “Soy Inside”Study 1. The Curse of “Soy Inside”

Study 2.. Descriptive Labels in the Study 2.. Descriptive Labels in the CafeteriaCafeteria

Now with Soy

1. The Curse of “Soy Inside”1. The Curse of “Soy Inside”

Can Labels make us taste what we believe we will taste?Can Labels make us taste what we believe we will taste?• To the untrained palate, taste can be subjectiveTo the untrained palate, taste can be subjective• Labels might provide the Power-of-Suggestion Labels might provide the Power-of-Suggestion

Phantom Ingredient TestPhantom Ingredient Test

Two Identical PowerBarsTwo Identical PowerBars• One says “contains 10 grams of soy protein”One says “contains 10 grams of soy protein”• One says “contains 10 grams of protein”One says “contains 10 grams of protein”

Taste This New ProductTaste This New Product• 70 adults taste and rate “soy” label70 adults taste and rate “soy” label• 70 adults taste and rate “----” label70 adults taste and rate “----” label

Now with SoyWansink, Brian and Se-Bum Park (2002), “Sensory Suggestiveness and Labeling: DoSoy Labels Bias Taste?” Journal of Sensory Studies, 17:5 (November), 483-491.

Sensory Suggestive WordsSensory Suggestive Words

Phantom Ingredient TestPhantom Ingredient Test• Exact same PowerBarExact same PowerBar• No soy in themNo soy in them

““Bad News”Bad News”• People “taste” the non-People “taste” the non-

existent soy and rate it lowexistent soy and rate it low

““Good News”Good News”• They think it’s healthyThey think it’s healthy (but they still hate it)(but they still hate it)• Differences across segmentsDifferences across segments

00.5

11.5

22.5

33.5

44.5

NoSoy

Label

SoyLabel

TasteTextureAppearanceHealthy

Now with Soy

Wansink, Brian and Se-Bum Park (2002), “Sensory Suggestiveness and Labeling: DoSoy Labels Bias Taste?” Journal of Sensory Studies, 17:5 (November), 483-491.

3. Sensory Suggestiveness:3. Sensory Suggestiveness: Descriptive Labels in the Descriptive Labels in the

CafeteriaCafeteria How Suggestive is Our Palate?How Suggestive is Our Palate?

• Goal: Improve perception of cafeteria food?Goal: Improve perception of cafeteria food?• Descriptive vs. non-descriptive labels Descriptive vs. non-descriptive labels • Six week field study -- six products; rotated labelsSix week field study -- six products; rotated labels• Self-selected -- evaluations Self-selected -- evaluations afterafter dining dining

Will there be a Benefit or a Backfire?Will there be a Benefit or a Backfire?• Benefit --> Wow . . . I feel like I’m in Brussels!Benefit --> Wow . . . I feel like I’m in Brussels!• Backfire --> I’m disappointed …this is dry chocolate cakeBackfire --> I’m disappointed …this is dry chocolate cake

Seafood filet Seafood filet

Chocolate CakeChocolate Cake

Succulent Italian Succulent Italian Seafood filetSeafood filet

Belgium Black Forest Belgium Black Forest Chocolate CakeChocolate Cake

Wansink, Brian, James M. Painter, and Koert van Ittersum, (2001) “Descriptive MenuLabels’ Effect on Sales,” Cornell Hotel and Restaurant Administrative Quarterly, 42:6(December), 68-72.

““Well, I know what I like” Well, I know what I like” --> Maybe Not--> Maybe Not

People evaluate descriptive foods as People evaluate descriptive foods as more favorablemore favorable

• Better taste, better texture, but as having Better taste, better texture, but as having more calories more calories

CaveatsCaveats• All foods were of acceptable qualityAll foods were of acceptable quality

Assimilating NOT contrastingAssimilating NOT contrasting• Self-selection (vs. realism)Self-selection (vs. realism)

Next stepsNext steps• Finding the point of reversalFinding the point of reversal• Moving this into the home . . .Moving this into the home . . .

012345678

DescriptiveLabel

Plain Label

TasteTextureCalories

Wansink, Brian, James M. Painter, and Koert van Ittersum, (2001) “Descriptive MenuLabels’ Effect on Sales,” Cornell Hotel and Restaurant Administrative Quarterly, 42:6(December), 68-72.

Thank You . . .Thank You . . .

Professor Brian WansinkProfessor Brian WansinkFood & Brand Lab -- DirectorFood & Brand Lab -- Director

Cornell UniversityCornell University

Professor Brian WansinkProfessor Brian WansinkFood & Brand LabFood & Brand Lab350 Wholers Hall350 Wholers Hall

University of IllinoisUniversity of IllinoisChampaign, IL 61820Champaign, IL 61820

[email protected]@UIUC.edu

Www.ConsumerPsychology.comWww.ConsumerPsychology.com

food psychology and overeating professor brian wansink food & brand lab -- director

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